Salt management system for portable renewable energy microgeneration system

ABSTRACT

A renewable energy microgeneration apparatus is disclosed that includes a mixing tank that mixes waste with a liquid, a buffer tank that receives and pre-warms the mixed waste, a pasteurization tank that pasteurizes on the pre-warmed mixed waste, a digestion tank that performs anaerobic digestion on the pasteurized waste, a de-watering device that separates liquid digestate and removes salt from the liquid, sensors that measure salinity and biogas quality, and a controller. The controller causes the transfer of digestate from the digestion tank to the pasteurization tank to the dewatering device, causes the de-watering device to separate the liquid and remove the salt from the liquid, monitors the salinity of the liquid and the quality of biogas using the sensors, and causes the mixing of the liquid with the waste and adjusts the feed rate of the waste to reduce the salinity of the waste and increase methane production.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to currently-pending U.S. provisionalapplication Ser. No. 62/599,359, filed Dec. 15, 2017, and 62/620,628,filed Jan. 23, 2018. The present application also is related tocurrently-pending U.S. application Ser. No. 15/596,479, filed May 16,2017, which is a continuation of U.S. application Ser. No. 14/995,407,filed Jan. 14, 2016, now U.S. Pat. No. 9,682,880, which is acontinuation of U.S. application Ser. No. 13/910,682, filed Jun. 5,2013, now U.S. Pat. No. 9,272,930, which is a continuation of U.S.application Ser. No. 13/526,024, filed Jun. 18, 2012, now U.S. Pat. No.8,465,645, which is a continuation of U.S. application Ser. No.13/085,320, filed Apr. 12, 2011, now U.S. Pat. No. 8,221,626, whichclaims the benefit of U.S. Provisional Application Ser. No. 61/323,186,filed Apr. 12, 2010, and U.S. Provisional Application Ser. No.61/348,689, filed May 26, 2010. The disclosures of those patents andpatent applications are hereby incorporated in their entirety byreference as if fully set forth herein.

FIELD OF THE INVENTION

The present invention relates to an improved method and device forproviding renewable energy and making users less dependent on localutility providers by recycling their organic waste onsite. Moreparticularly, the present invention relates to improvements to ananaerobic digester that allows users to convert organic waste intosustainable energy.

BACKGROUND OF THE INVENTION

There is a need in the art for a renewable energy microgeneration systemin a single, modular, portable configuration that will allow users toconvert organic waste into sustainable energy onsite. There also is aneed in the art for a renewable energy microgeneration system with areduced footprint, with separate containers for its differentcomponents, with modular interconnectivity between those containers, andwith increased throughput.

SUMMARY OF THE INVENTION

To address at least the problems and/or disadvantages described above,it is a non-limiting object of the present invention to provide aportable and modular renewable energy microgeneration apparatus. Therenewable energy microgeneration apparatus includes a first modularunit, a second modular unit, a third modular unit, and fourth modularunit. The first modular unit, the second modular unit, the third modularunit, and the fourth modular unit are portable in that they areconfigured to be transported to a site and placed in fluid communicationwith each other at the site. The first modular unit, the second modularunit, the third modular unit, and the fourth modular unit also aremodular in that they can be combined with each other in differentnumbers and configurations.

The first modular unit includes a mixing tank that is configured to mixwaste with a liquid and a chopper in fluid communication with the mixingtank that is configured to reduce the waste to smaller sized components.The second modular unit includes a buffer tank configured to receive thewaste from the first modular unit and pre-warm the waste in preparationfor pasteurization and a plurality of first holding tanks that areconfigured to receive the waste from the buffer tank and performpasteurization on the waste. The third modular unit includes one or moresecond holding tanks that are configured to perform anaerobic digestionon the waste, each of the one or more second holding tanks being largerin volume than each of the plurality of first holding tanks. And thefourth modular unit includes one or more third holding tanks that areconfigured to store gas generated by the waste in at least one of themixing tank, the chopper, the buffer tank, the plurality of firstholding tanks, the one or more second holding tanks, and the one or morethird holding tanks. Each of the mixing tank, the chopper, the buffertank, the plurality of first holding tanks, and the one or more thirdholding tanks is sized to support anaerobic digestion in a plurality ofthird modular units.

In certain embodiments, the second modular unit further includes aliquor tank configured to store liquid that is removed from the wasteafter anaerobic digestion is performed on the waste. In addition, therenewable energy microgeneration apparatus may further include a fifthmodular unit, the fifth modular unit comprising a de-watering devicethat is configured to separate what remains of the waste after anaerobicdigestion is performed into solid waste and liquid waste, wherein thefifth modular device is portable and modular in the same manner as thefirst modular unit, the second modular unit, the third modular unit, andthe fourth modular unit. The fifth modular unit also may include a saltremoval system configured to remove salt from the liquid waste output bythe de-watering device. The fifth modular unit also may include abagging system configured to place solid waste output by the de-wateringdevice into standard sized containers.

Also in certain embodiments, renewable energy microgeneration apparatusmay include an odor management system configured to remove gas fromwithin at least one of the first modular unit, the second modular unit,and the third modular unit; filter odors from the gas removed from thefirst modular unit, the second modular unit, and the third modular unit;and vent to atmosphere the gas removed from the first modular unit, thesecond modular unit, and the third modular unit, wherein the gas removedfrom the first modular unit, the second modular unit, and the thirdmodular unit differs from the gas generated by the waste in at least oneof the mixing tank, the chopper, the buffer tank, the plurality of firstholding tanks, the one or more second holding tanks, and the one or morethird holding tanks. The renewable energy microgeneration apparatus alsomay include a CO₂ extraction system configured to separate CO₂ from thegas generated by the waste in at least one of the mixing tank, thechopper, the buffer tank, the plurality of first holding tanks, the oneor more second holding tanks, and the one or more third holding tanks;and inject the CO₂ into the one or more second holding tanks to stir thewaste in the one or more second holding tanks.

In addition, each of the first modular unit, the second modular unit,the third modular unit, and the fourth modular unit may be disposed in aportable container, with each container being configured to withstandexplosions of a predetermined magnitude without compromising an adjacentcontainer. The first modular unit, the second modular unit, the thirdmodular unit, and the fourth modular unit may be combined with eachother in different numbers and configurations using piping and wiringdisposed within the portable container of each of the first modularunit, the second modular unit, the third modular unit, and the fourthmodular unit; and the piping and wiring are configured to be connectedand disconnected via connection points housed within the portablecontainer of each of the first modular unit, the second modular unit,the third modular unit, and the fourth modular unit. Furthermore, therenewable energy microgeneration apparatus may include a natural gasboiling configured to generate at least of electricity and heat from thegas removed from the at least one of first modular unit, the secondmodular unit, and the third modular unit.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present invention can be better understood with referenceto the following drawings, which are part of the specification andrepresent preferred embodiments of the present invention:

FIG. 1A is an isometric view that illustrates an example of an apparatusfor renewable energy microgeneration according to a non-limitingembodiment of the present invention;

FIG. 1B is an isometric view that illustrates the apparatus of FIG. 1Awith the containers and compressor enclosure removed;

FIG. 1C is a plan view that illustrates the apparatus of FIG. 1B;

FIG. 1D is an elevation view that illustrates the apparatus of FIG. 1C;

FIG. 1E is a schematic diagram of the apparatus of FIGS. 1A-1CD

FIG. 2 is an isometric view that illustrates a chopper unit according toa non-limiting embodiment of the present invention;

FIG. 3 is an isometric view that illustrates a de-watering unitaccording to a non-limiting embodiment of the present invention;

FIG. 4 is schematic diagram that illustrates a controller according to anon-limiting embodiment of the present invention;

FIG. 5 is an isometric cutaway view that illustrates a gas storage tankaccording to a non-limiting embodiment of the present invention;

FIG. 6 is schematic diagram that illustrates water and waste pipingaccording to a non-limiting embodiment of the present invention;

FIG. 7 is schematic diagram that illustrates gas piping according to anon-limiting embodiment of the present invention;

FIG. 8 is schematic diagram that illustrates a 6-ton per dayconfiguration of the present invention;

FIG. 9A is and isometric view that illustrates an example of anapparatus for renewable energy microgeneration according to anothernon-limiting embodiment of the present invention;

FIG. 9B is and isometric view that illustrates an example of anapparatus for renewable energy microgeneration according to anothernon-limiting embodiment of the present invention;

FIG. 9C is and schematic drawing that illustrates the apparatus of FIG.9B;

FIG. 10A is an isometric view that illustrates a chopper unit accordingto the non-limiting embodiment of the present invention depicted inFIGS. 9A and 9B;

FIG. 10B is an isometric view that illustrates another chopper unitaccording to a non-limiting embodiment of the present invention depictedin FIGS. 9A and 9B;

FIG. 11 is an isometric view that illustrates a command unit accordingto a non-limiting embodiment of the present invention depicted in FIGS.9A and 9B;

FIG. 12 is an isometric view that illustrates a digester unit accordingto a non-limiting embodiment of the present invention depicted in FIGS.9A and 9B; and

FIG. 13 is an isometric view that illustrates a de-watering unit with abagging system according to a non-limiting embodiment of the presentinvention.

The components in the drawings are not necessarily to scale, emphasisinstead being placed upon illustrating the principles of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention overcomes the shortcomings of the prior artdiscussed above and offers at least the advantages discussed below byproviding a renewable energy microgeneration system in a single,modular, portable configuration that allows users to convert organicwaste into sustainable energy onsite. Moreover, it provides a portablerenewable energy microgeneration system with a reduced footprint, withmodular components and component groupings, and with increasedthroughput. Accordingly, it can be sized to suit a specific user's needsand can be installed and connected to conventional power systems sothat, within a matter of weeks (or hours if the system pre-seeded withlive digestate), a user can create his or her own energy for heating,hot water, and/or general electricity needs.

In more detail, the components of the renewable energy microgenerationsystem work together to perform an anaerobic digestion process thatgenerates heat, electricity, biogas, and fertilizers from what wouldotherwise be considered “waste.” Through its unique configuration, thepresent invention is able to provide all of the components needed tocomplete that process in one or more self-contained shipping containers,thereby providing a portable system that can be conveniently connectedto a wide variety of structures (e.g., homes, industrial buildings, andoutdoor facilities). Moreover, its mobility makes it practical for awide variety of applications, such as providing power in remotevillages, at remote cellular towers, and in war zones or disaster reliefareas where waste is plentiful and power and/or heat are in high demand.

In addition to providing power and heat, the renewable energymicrogeneration system of the present invention also provides a “green”solution to waste management, maximizing the amount of useful energythat can be harnessed from organic materials. It effectively eliminatesthe costs of waste removal by providing the user with a close,convenient place to dispose of his or her waste. It also helps eliminaterunoff pollution. And, in addition to allowing the user to recycle hisor her organic waste onsite, the renewable energy microgeneration systemof the present invention also reduces pollution by making the user lessdependent on utility companies that generate pollution with theirvarious methods of energy production. Moreover, it reduces carbonemissions from waste transport to a centralized processing facility,such as a dump or a larger-scale anaerobic digestion system.

Those and other advantages provided by the present invention can bebetter understood from the description of the preferred embodimentsbelow and in the accompanying drawings. In describing the preferredembodiments, specific terminology is resorted to for the sake ofclarity. However, the present invention is not intended to be limited tothe specific terminology so selected, and it is to be understood thateach specific term includes all technical equivalents that operate in asimilar manner to accomplish a similar purpose.

A. Apparatus for Renewable Energy Microgeneration

Turning to the drawings, FIGS. 1A-1D provide various views of anexemplary apparatus for renewable energy microgeneration 100(hereinafter “the REM apparatus 100”) according to a non-limitingembodiment of the present invention, and FIG. 1E provides a schematicdiagram of the REM apparatus 100 according to a non-limiting embodimentof the present invention. That REM apparatus 100 includes a firstcontainer 102 and a second container 104 that provide portableenclosures that house the various components 106-128 of the REMapparatus 100. The first container 102 houses a chopper unit 106, abuffer tank 108, two small holding tanks 110, a large holding tank 112,a de-watering unit 114, a gas scrubber 116, and an electronic controlunit (ECU) 118. And the second container 104 houses a gas storage unit906 that includes a gas storage tank 120. The REM apparatus 100 alsoincludes biogas engine 122 disposed adjacent to the second container104; a flare 124 disposed on the outside of the first container 102; aliquor tank 126 disposed adjacent to the first container 102; acompressor 128 disposed in a compressor enclosure 130 adjacent to thefirst container 102; and various pumps 132A-132D, valves 134A-134C,piping 136A-136C, and wiring connections 138 for functionally tyingthose components 106-128 together. The components 106-128 provided in,on, and adjacent to those containers 102 and 104 work together toperform an anaerobic digestion process that generates heat, electricity,biogas, and fertilizers from waste/muck in a mobile, modular renewableenergy microgeneration system.

The chopper unit 106 is where muck/waste deposits are loaded into theREM apparatus 100 and it functions to mix that the muck/waste loadedinto the REM apparatus 100 and to mix it with liquid (e.g., potableand/or grey water). The buffer tank 108 functions to store and pre-warmthe water/muck/waste mixture produced with the chopper unit 106. Thesmall holding tanks 110 function to pasteurize the pre-heatedwater/muck/waste mixture produced with the buffer tank 108 or, whenpasteurization is not required for the overall anaerobic digestionprocess, to partially digest that pre-heated water/muck/waste mixturevia thermophilic anaerobic digestion. The large holding tank 112functions to produce mesophilic anaerobic digestion with the partiallypasteurized or digested water/muck/waste mixture produced with smallholding tanks 110. The de-watering unit 114 functions to remove liquidsfrom what remains of the water/muck/waste after anaerobic digestion iscompleted in the small holding tanks 110 and/or the large holding tank112. The gas scrubber 116 functions to clean the biogas produced duringthermophilic and/or mesophilic anaerobic digestion in the small holdingtanks 110 and/or the large holding tank 112, respectively. The gasstorage tank 120 functions to store the cleaned biogas produced with thegas scrubber 116. The biogas engine 122 functions to simultaneouslygenerate electricity and heat from the cleaned biogas stored in the gasstorage tank 120. The ECU 118 functions to control the flow of liquid,muck/waste, water/muck/waste, and biogas through the REM apparatus 100as required to generate heat, electricity, biogas, and fertilizers in acontinuous, regenerative cycle. The flare 124 functions to safely burnsurplus biogas. And the compressor 128 functions to generate compressedair for stirring the water/muck/waste mixture in the small holding tanks110. The containers 102 and 104 and each of those components 106-128 areaddressed separately below.

i. Containers 102 and 104

To enable the REM apparatus 100 to be transported as modular units tosubstantially any location, the containers 102 and 104 that house thevarious components 106-128 of the REM apparatus 100 are configured tocomply with the size and weight requirements of the relevant highwayregulatory and governmental agencies. In FIG. 1A, for example, the firstcontainer 102 (shown with top removed) is a standard 40-foot “High Cube”shipping container (40 ft×8 ft×9.5 ft; Payload: 60,350 lbs; Capacity:2,376 ft³) and the second container 104 (also shown with top removed) isa standard 20-foot shipping container (Dimensions: 19.8 ft×8 ft×8.5 ft;Payload: 48,600 lbs; Capacity: 1,164 ft³). Such containers arespecifically designed to be handled by ship-to-shore gantry cranes, tobe stacked and stored on a container ship, and to be attached to acontainer transport trailer, thereby making those containers 102 and 104particularly suited for commercial land and sea transport. Thosecontainers 102 and 104 are also particularly suited for military airtransport using certain military aircraft, such as Sikorsky SKYCRANEbrand helicopter and the Lockheed C-130 HERCULES brand airplane. Otherstandard containers may also be used (e.g., 45-foot and 30-footcontainers).

As an alternative to the configuration depicted in FIGS. 1A-1D, thevarious components 106-128 of the REM apparatus 100 also may be housedin a plurality of smaller containers (e.g., a combination of 10-foot and20-foot shipping containers rather than a 40-foot shipping container 102in combination with a 20-foot shipping container 104). As depicted inFIGS. 9-19, for example, the chopper unit 106 may be housed in a 10-footcontainer 1000, while a command unit 902, a digester unit 904, the gasstorage unit 906, and the dewatering unit 114 may be housed in separate20-foot containers 104, 1100, 1200, and 1300. The REM apparatus 900 mayinclude one of each of these units 106, 114, 902, 904, and 906, or itmay include a plurality of one of more of each of these units 106, 114,902, 904, and 906, as required to expand capacity according to the needsof the user. For example, one chopper unit 106, one command unit 902,one gas storage unit 906, and one dewatering unit 114 may be configuredto be used with between one and five digester units 904 such thatincreased CHP production is achieved with the addition of each digesterunit 904, but without the need to increase the footprint of the REMapparatus 900 and without the need for additional chopper units 106,command units 902, the gas storage unit 906, or dewatering units 114.The separation of these units 106, 114, 902, 904, and 906 in this mannerallows for more unique stacking configurations, particularly in a cityenvironment where 40-foot shipping containers may not be a feasibleoption. Additionally, the separation of these units 106, 114, 902, 904,and 906 allows for spacial separation of the various units 106, 114,902, 904, and 906, particularly the digester unit 904 and the gasstorage unit 906, for safety and other considerations.

In addition, the containers of the REM apparatus 100 and 900 may includeall piping 136A-136C and 1006 internally for safety during operation.Additionally, the internal piping configuration allows for the safetransport of the various containers by minimizing the chance for damageto external components of the standardized containers.

The REM apparatus 900 may comprise a chopper unit 106, stored in a10-foot container, that houses, a shutter door 1014, bin lifter (notdepicted), a hopper 200, a hopper scraper 1018, a feed auger 1020, ahomogenizing pump 204, a feed pump 132A, a liquor dosing system 1008,and an odor abatement pipeline 1006, as depicted in FIG. 10B. As above,the chopper unit 106 is where muck/waste deposits are loaded into theREM apparatus 900 and it functions to mix that the muck/waste loadedinto the REM apparatus 900 and to mix it with liquid (e.g., potableand/or grey water). The separation of the chopper unit 106 from thecontainer 102 allows for multiple chopper units 106, a variety ofchopper unit styles, or the complete removal of the chopper unit 106.The command unit 902, stored in a 20-foot container, may comprise theECU 118, the buffer tank 108, the liquor tank 126, the small holdingtanks 110, a central drainage line 1007, and an odor abatement pipeline1006. The command unit 902 provides similar functionality as each of thecomponent parts of the system described previously. The separation ofthe command unit 902 from container 102 gives the REM apparatus 900 theflexibility to use a single command unit 902 with multiple chopper units106 or multiple digester units 904. Digestate from the command unit 902travels to the digester unit 904, stored in a 20-foot container, whichmay comprise the large holding tank 112, a large holding tank heatingsystem 1206, a large holder tank recirculation system 1208, a largeholder tank discharge pump 1204, a large holder tank pressure reliefvalve 164, methane sensor 1202, and a large holder tank drainageconnection 1210. Storing the large holding tank in a separate containerallows for users to significantly scale up the power generated from theREM apparatus 900 by simply adding more digester units 904 and/or gasstorage unit 906. The biogas generated by the digester unit 904 isscrubbed by the gas scrubber 116 and stored in the gas storage tank 120.The gas storage tank 120, contained in a 20-foot container, may comprisea flexible bladder 500, a gas holder discharge system, and a gas levelswitch assembly. The odor abatement unit 908 may comprise the centralodor abatement pipeline 1006, which is used to transfer odorousatmosphere from the components of the REM apparatus 900 to the odorabatement unit 908. The heating system comprises the central heatingpipeline and the boiler system 922. The combined heat and power unit(CHP) may comprise the gas scrubber 116, the prime mover, the generator918, and the heat recovery system. The grid connection interface cabinet920 comprises at least a protection device (not depicted), animport/export meter (not depicted), and a gas leak detection device (notdepicted).

a. Base

The first container 102 includes a concrete base that houses some of thepiping 136A-136C that interconnects the components 106-128 of the REMapparatus 100. In manufacture, that piping 136B and 136C is assembledusing a jig to ensure that all the components 106-114 can be positionedcorrectly in a repeatable, modular manner. The jig is manufactured usingan inverse profile of those components 106-114. A straw-based concreteis preferably used to form the base of the container 102 because it is asustainable material that provides a certain degree of flexibilitywithin the concrete base.

The concrete base is designed to support the various components 106-114in the first container 102 by following the profile of the tank bases.That configuration not only provides stability along with the exteriorwalls that hold the tanks in place, it also braces those components106-114 so as to ensure the pipe fittings will not shear in transport.Those components 106-114 may be further braced within the container 102with insulation designed to fit tightly between those specificcomponents 106-114 and the container 102. In the alternative, the baseof the first container 102 may include a metal framework to createstrength and allow for glide entry of the components 106-114 into thefirst container 102.

b. Facia 140 and Loading Platform 142

The first container 102 also includes facia 140 and a loading platform142 at one end of for use in loading muck/waste into the chopper unit106 and for unloading fertilizer output by the de-watering unit 114. Thefacia 140 includes a door 144 that can be opened to allow users accessto the various components 106-114 housed therein. The first container102 also includes a pair of external double doors 146 at the same end ofthe first container 102 as the facia 140. Although those doors 144 arenot shown on the first container 102 for purposes of clarity, they areclearly shown on the second container 104. Those doors 146 are of thetype typically found on a conventional 40-foot or 20-foot shippingcontainer.

The facia 140 provides protection to the user from the components106-114 housed in the first container 102. And the door 144 providesaccess for maintenance and safety checks to be performed on thosecomponents 106-114. The facia 140 may also include access panels (notshown) for accessing parts on the far sides of the components 106 and114 that are disposed adjacent to the facia 140 so as to provide themaximum amount of access and maneuverability to users that need toperform maintenance and/or safety checks on those components 106 and114.

The loading platform 142 is configured allow muck/waste to be loadedinto the chopper unit 106 and to allow solid waste (e.g., mulch) to betransported away from the de-watering unit 114 using a wheelbarrow orother comparable wheeled transport device. The loading platform 142 isalso configured to fold up between the facia 140 and the pair of doubledoors 146 so it can be stowed away during transport of the firstcontainer 102. A control box 148 for operating and monitoring the REMapparatus 100 via the functionality of the ECU 118 is also provided onthe facia 140 and will be folded up behind the double doors 146 of thesecond container 102 during transport. Emergency stop and full shut offsare also located on the facia 140. Because there should not be a need toaccess the gas storage tank 120 after the REM apparatus is placed intooperation (other than routine maintenance and safety checks) thatcomponent 120 preferably remains secured behind the double doors 146 ofthe second container 104 during transport and during operation of theREM apparatus 100.

The loading platform 142 is strong enough to support significantly moreweight than that of the user so large amounts of muck/waste can beloaded into the anaerobic digester at one time. A ramp 150 is also beprovided with the loading platform 142 to allow wheeled transportdevices, such as wheelbarrows, to be easily moved to and from the top ofthe loading platform 142. The ramp 150 is constructed from standardsquare tubes, welded together with mesh spot welds on the top, whichprovides a tractable surface for all weather conditions. The ramp 150 isremovably attached to the loading platform 142 using angled hooks thatclip into a corresponding receiver on the loading platform 142, whichallows users, such as horse yards, to remove the ramp 150 and use theirexisting ramps in its place. The loading platform 142 and ramp 150 arepreferably made from galvanized steel to protect them from the elementsand to reduce manufacturing costs. And the legs of the platform 142 andramp 150 are preferably adjustable according to different terrain toprovide maximum stability, such as on uneven surfaces.

In the REM system 900 that comprises a plurality of smaller containers106-128 and 902-908, the chopper unit 106, which is where muck/waste areloaded into the system, may comprise a catering mouth 1002, instead of afacia 140, as depicted in FIG. 10A. The catering mouth 1002 includes aroller shutter door (not depicted) that extends the width of the chopperunit 106 to allow larger quantities of muck/waste to be processed by thechopper. The roller shutter door of the catering mouth 1002 opens andcloses vertically, although other embodiments may incorporate other doormechanisms based on the application. The catering mouth 1002 allowsaccess to load feedstock into the hopper inside the container at areasonable height without the need for a loading platform. A safetyinterlock system prevents all chopper operations while the cateringmouth 1002 is open.

In another embodiment, the REM system 900 may include a separate septicinput option (not depicted) which may be used in conjunction with, orinstead of, the facia 140 or the catering mouth 1002. This septic inputoption would funnel septic or sludge waste directly into either thechopper unit 106 or into the buffer tank 108. This septic input providesanother mechanism for users to drive the anaerobic digestion of the REMapparatus 100 or 900 based on the type of muck/waste generated by theuser. This septic input option may also provide a pipeline foralternative types of grey water/muck/waste to be inputted into thesystem. The chopper unit 106 may be configured to fit behind the doorsof a standard container to allow for shipping of the chopper unit 106.The contents 108-128 of the other containers 902-908 also should beconfigured to fit behind the doors of a standard container to allow forshipping.

c. Ventilation

A forced ventilation system is preferably incorporated into eachcontainer 102 and 104 to prevent build-up of an odorous and explosiveatmosphere. That forced ventilation system includes an electric fan (notshown) that generates a pressure differential between the inside of eachcontainer 102 and 104 and the atmosphere so as to circulate air througheach container 102 and 104 via louvers 152 provided therein. Thatprocess not only prevents dangerous gases from building up in thecontainers 102 and 104, it also removes heat to help cool the machinerylocated in the first container 102. A roof circular vent (not shown) mayalso be provided to allow heat to escape while preventing the ingress ofwater. If the electric fan fails, the ECU 118 will produce an alarm andinitiate shutdown of the various components 106-128 of the REM apparatus100.

The ventilation system may also include an air sparge system (notdepicted) designed to ensure a certain level of oxygen to be presentinside the various containers in the REM apparatus 100 and 900 toprohibit the production of biogas inside the various containers throughthe process of anaerobic digestion. The air sparge system consists of alinear air pump (not depicted) that pumps air into an air line. The airline is fed into the necessary tanks near the base of the tank, where itforms a perforated loop that allows an even release of air. The linearair pump is electrically driven. It is sized to deliver sufficient airto inhibit the production of biogas and, in case any gas is produced, tosufficiently dilute these gases to prevent a flammable or explosivecondition inside the tank. The air sparge system is manufactured frommaterials that provide resistance to corrosion and erosion for 20 years.

Additionally, the forced ventilation system and the roof circular ventmay be attached to an odor abatement pipeline 1006 (FIG. 10) to transferthe odorous or explosive atmosphere to be processed. In this embodiment,only the excess atmosphere that is unable to be sent to the through theodor abatement pipeline 1006 to the odor abatement system 908 (FIG. 11)will be vented.

d. Roof

The first container 102 and second container 104 may include radiatorroofs that use flexible water piping 136A to heat water using the sun'senergy. Because such standard containers have grooves formed in theirroofs, the flexible water piping 136A can be laid out in those grooves.That water piping 136A will be is covered with a UV-protected plasticsheet to encapsulate heat and, in turn, heat the water within thatpiping 136A. Solar panels may also be placed on the roofs of the firstcontainer 102 and the second container to heat water and/or generateelectricity using the sun's energy. That warm water and electricity canbe used to support the operation of the other components 106-128 of theREM apparatus 100 (e.g., heating muck/waste and/or powering pumps132A-132D and other electronics) and/or it can be used to supplement theheat and electricity generated with the biogas engine 122. Rain watermay also be harvested from the roofs of the containers 102 and 104 foruse in the chopper unit 106. The roofs may also include a lightning rod,or equivalent device, for protecting the containers 102 and 104 andtheir contents from lightning strikes.

Additionally, solar thermal/electric panels may be incorporated orattached to the roofs of the containers 102, 104, 1000, 1100, 1200, and1300 in order to supplant the CHP used by the REM apparatus 100 and 900.These solar panels may be controlled by the ECU 118.

ii. Chopper Unit 106

The chopper unit 106 may be disposed at a distal end of the firstcontainer 102. Alternatively, the chopper unit 106 may be housed in aseparate, 10-foot container 1000, as depicted in FIGS. 9-10. The chopperunit 106 functions as the input facility for loading muck/waste depositsinto the REM apparatus 100 or 900. The chopper unit 106 also may includean air compressor (not depicted) for use in automatically opening andclosing valves 134 therein.

As FIG. 2 illustrates, the chopper unit 106 may include a hopper 200, amixing tank 202, and a homogenizing pump 204. The hopper 200 is formedas the opening of the chopper unit 106 to facilitate easier loading ofmuck/waste therein. The hopper 200 includes a pair of doors 206 thatmust be opened to load the chopper unit 106. Those doors 206 areaccessible at the facia 140 of the first container 102 and are heldclosed with magnetic catches. The hopper 200 is preferably made fromstainless steel or other corrosion resistant material (e.g., galvanizedsteel) because it is likely to be hit and scratched by shovels/spades orother loading equipment, and the doors 206 are preferably made of adurable transparent material (e.g., plexiglass) so a user can view themixing/macerating process when the doors 206 are closed. Those doors 206also provide a safety feature by preventing operation of the chopperunit 106 when they are opened, thereby preventing a user or a tool frombeing pulled into the mixing tank 202 by the homogenizing pump 204. Thatfunctionality is controlled by the ECU 118.

As depicted in FIG. 10A and noted above, the chopper unit 106 maycomprise a catering mouth 1002 with automated roller shutter doorsinstead of a pair of hinged doors 206. The catering mouth 1002 allowsaccess to load feedstock into the hopper 200 inside the container at areasonable height. A safety interlock system prevents all chopperoperations while the shutter door is open. The chopper unit 106 may alsoinclude a septic input option (not depicted) which feeds directly intothe mixing tank 202. The catering mouth 1002 may be housed within a10-foot shipping container, with container blocks on each corner of thecontainer, to enable the handling and stacking advantages of shippingcontainers. Multiple chopper units 106 can be integrated into the REMapparatus as needed. The container is modified to provide an opening forthe roller shutter door and to allow pipework for input and output topenetrate the container sides. All openings and penetrations arereinforced to maintain structural integrity. The cargo doors areretained to provide access for maintenance. With the cargo doors of thecontainer 1000 and the roller shutter door of the catering mouth 1002closed (e.g. when not in maintenance), the container is fully enclosedon all sides to prevent rodents, birds and other animals from entering.A safety interlock prevents all operation while the container doors areopen.

The roller shutter door of the catering mouth 1002 allows access to loadfeedstock into the receiving hopper 200 inside the container 1000. Thedoor is controlled via the control unit 1022 on the outside of thechopper unit 106. A safety interlock prevents all chopper operationwhile the shutter door 1002 is open. The chopper unit 106 can be loadedwith feedstock manually or can be equipped with a bin-lifter (notdepicted) to assist the loading process. The loading mechanism may varyper case and is selected based on the waste collection characteristics(waste container type and size, frequency, etc.) of a specific case. Inthis embodiment, the loading point of the chopper unit 106 is referredto as a catering mouth 1002 because it is particularly suitable forreceiving and processing food waste.

The chopper unit 106 also functions to homogenize the muck/waste that ismoved into the mixing tank 202 via the hopper 200. Liquid (e.g., potableand/or grey water) is fed into the chopper unit 106 via water piping136A and mixed with the muck/waste in the mixing tank 202 using thehomogenizing pump 204 to re-circulate, macerate, and homogenize theliquid and muck/waste. Alternatively, the liquid fed via the waterpiping 136A may be use grey water stored in the liquor dosing tank 1009to remove the need for external potable water. The water/muck/wastemixture is chopped finely enough by the homogenizing pump 204 that itwill not clog the waste valves 134B or the waste piping 136B of the REMapparatus 100 as it moves between the components 106-114 thereof. Liquidis pumped into the mixing tank 202 by a mixer feed pump 132A as requiredto provide the proper mixture of liquid and muck/waste in the mixingtank 132 required for hydrolysis. That flow rate is controlled by theECU 118 based on the amount of muck/waste deposited in the mixing tank202. And the liquid is preferably grey water that is re-circulated fromthe de-watering unit 114 back into the mixing tank 202 in a regenerativemanner to further add to the efficiency of the REM apparatus 100.

The mixing tank 202 is positioned below with hopper 200 so muck/waste isfed directly into the mixing tank 202 via the hopper 200. The mixingtank 132 preferably includes an integrated stone trap 154 (FIG. 1E) tocatch larger debris that that might clog the waste valves 136B or thewaste piping 128B. The stone trap 154 will need to be discharged onregular basis determined after commissioning of the REM apparatus 100and is therefore preferably accessibly via an access hatch in the facia140. The chopper unit 106 can be sized to meet the output requirementsof the user and/or the particular type(s) of muck/waste being processed.And because muck/waste types generally have high volume and low weightor high weight and low volume, the mixing tank 202 will have a visiblelevel marker to which the mixing tank 202 can be filled withsubstantially any type of muck/waste without exceeding the limits of theREM apparatus 100.

The volume indicated by that level marker (e.g., 60 Liters) includesboth the muck/waste loaded into the mixing tank 202 by the user and theliquid fed into the chopper unit 106 via the water piping 136A. The ECU118 will automatically determine the appropriate amount of liquid to mixwith the waste/muck based on the weight and type of the waste/muck. Forexample, very dry and/or dense waste/muck (e.g., horse manure) mayrequire a dilution ratio up to 9:1, while wetter and/or less densewaste/muck (e.g., vegetable waste) may require a dilution ration ofaround 4:1. Because the dense waste/muck necessarily weighs less thanthe less dense waste muck, the resulting overall volume ofwater/waste/muck in the mixing tank 108 will be the same regardless ofwhich of those types of waste/muck is placed therein (i.e., 15 kg horsemanure and 45 kg of vegetable waste will both fill a 60 Liter volumewhen the proper amount of liquid is added). The type and/or weight ofthe waste/muck can be input into the ECU 118 by a user and/orautomatically measured by the ECU 118, such as with an electronic scale,so the ECU 118 can determine the appropriate amount of liquid to mixwith that waste/muck.

In the REM apparatus 900 depicted in FIG. 9, the chopper unit 106 maycomprise the hopper 200, the homogenizing pump 204, the feed pump 132A,a liquor dosing system 1008, and an odor abatement pipeline 1006. Thehopper 200 can be reached by opening the roller shutter door of thecatering mouth 1002, which allows access through a rectangular openinglarge enough to receive loading from containers sized up to 360-literbins. The hopper assembly 200 comprises the receiving hopper 200, hopperscraper 1018, and a feed auger 1020, and auger motor 1012.

The loaded feedstock is received by a 2,000-liter receiving hopper 200that may allow 3,000 kg of fresh feedstock per day to be loaded in atleast four feeding sessions. The sides of the hopper 200 aresufficiently sloped to allow gravity to force the feedstock down to thebottom of the hopper 200, where it enters a trough that houses the feedauger 1020. The hopper 200 and the auger trough may be manufactured frommild steel with an appropriate coating to provide resistance tocorrosion and erosion for 20 years.

The hopper scraper 1018 is a pneumatically operated device that ismounted on one of the sloped sides of the receiving hopper 200. It isdesigned to assist the feedstock in the hopper 200 to enter the auger1020 and to prevent ‘bridging’ of feedstock in the hopper 200.

The feed auger 1020 is an electrically driven screw conveyer mounted inthe trough at the base of the hopper 200. It receives the feedstock fromthe hopper 200 and conveys it to the homogenizing pump 204. The auger1020 has an appropriate capacity that meets the through-put requirementsof at least 3,000 kg of feedstock per day.

The feed auger 1020 conveys the food waste from the receiving hopper 200into the homogenizing pump 204. The homogenizing pump 204 reduces theparticle size of the feedstock to a maximum of 5 mm. The specifichomogenizing pump 204 is selected based on appropriate throughputcapacity that allows at least 3,000 kg of feedstock per day to beprocessed. It has a facility that collects and allows easy removal oflarge, solid objects that cannot be processed, such as cutlery, crockeryand glass. Inside the homogenizing pump 204, the freshly maceratedfeedstock is mixed and diluted with liquor from the liquor dosing system1008.

a. Liquor Dosing System 1008

As depicted in FIGS. 10A and 10C, the liquor dosing system 1008 includesa dosing tank 1009 and a dosing pump 1010. The dosing tank 1009 is asmall polymer tank disposed inside the container 1000 that houses thechopper unit 106. It is filled with liquor from the liquor tank 126, andits content is used to mix with and dilute fresh, macerated feedstock toreduce the level of suspended solids in the feedstock flow. A levelindicator inside the dosing tank 1009 allows the ECU 118 to interruptall chopper operation when the dosing tank 1009 level is running low,allowing liquor flow from the liquor tank 126 into the dosing tank 1009when the dosing tank level is running low, and prevent liquor flow fromthe liquor tank 126 into the dosing tank 1009 when the dosing tank levelis high. The dosing pump 1010 is an electrically driven compactprogressive cavity pump that pumps the liquor from the dosing tank 1009into the homogenizing pump 204.

The liquor dosing system 1008 is operated as needed based on feedstockfluidity and is designed to reduce the level of suspended solids of thefresh feedstock to match the limitations of a dosing pump 1010 for aparticular waste stream or a particular market. The level of suspendedsolids may range from 6% to 72% (“feedstock dilution”). The liquordosing system 1008 automatically pumps part of the produced liquor fromthe liquor tank 126 in the command unit 902 or container 102 to thechopper unit 106. In the chopper unit 106, the liquor is mixed with thefreshly chopped feedstock to ensure the feedstock mix is sufficientlyfluid to be pumped through the system. Using liquor instead of freshwater for this process eliminates the requirement of additional cleanwater input and maximizes the amount of energy that is extracted fromthe feedstock during the digestion process. This process is controlledby the ECU 118 based on the feedstock processed. Dilution takes place inthe homogenizing pump 204, before the feed pump 132A, allowing thediluted mix to be pumped into the buffer tank 108 by the feed pump 132A.

The liquor dosing system 1008 also may include additional tanks (notdepicted) with segregation columns and sampling points. The segregationcolumns and sampling points include sensors for monitoring feedstockfluidity so the ECU 118 may better control the dosing process. Thesegregation columns and sampling points also may be configured to allowaccess by users of the REM apparatus 900 for manual and/or visualfluidity assessment.

b. Odor Abatement Pipeline 1006

The odor abatement pipeline 1006 in the chopper unit 106 is designed toabate the odor from at least the liquor dosing tank 1009, the buffertank 108, the small holding tanks 110, the large holding tank 112, andthe open air space above the receiving hopper assembly 200. The aircontained in the open air space above the receiving hopper assembly 200is actively attracted into the odor abatement pipeline 1006 by a fan.Alternatively, the connection to the tanks may be passive such that theair inside the tank is displaced through the pipeline during filling andemptying of the tank. The odor abatement pipeline 1006 leaves thechopper unit 106 through the wall of the container and is led into thesystem's external odor abatement system 908. The odor abatement system908 can optionally be installed in the command unit 902.

iii. Command Unit 902

The command unit 902 may be in housed in the container with variouscomponents 106-128, or may be stored separately in a 20-foot container.The command unit 902 may comprise the ECU 118, the buffer tank 108, theliquor tank 126, the small holding tanks 110, a central drainage line1007, and an odor abatement pipeline 1006. The command unit 902 providessimilar functionality as each of the component parts of the systemdescribed separately. However, the separation of the command unit 902from container 102 gives the REM apparatus 900 the flexibility to use asingle command unit 902 with multiple chopper units 106 or multipledigester units 904. Digestate processed from the command unit 902travels to the digester unit 904.

a. Buffer Tank 108

The buffer tank 108 receives the water/muck/waste mixture from thechopper unit 106 and stores it before moving it to the small holdingtanks 110. Because it is used for storage rather than just mixing, thebuffer tank 108 is sized larger than the mixing tank 202 of the chopperunit 106. The water/muck/waste mixture is moved from the mixing tank 202of the chopper unit 106 to the buffer tank 108 with the homogenizingpump 204 by opening one waste valve 134B and closing another so as toclose the re-circulation loop and re-redirect the water/muck/wastemixture to the buffer tank 108. The opening and closing of those wastevalves 134B is controlled by the ECU 118 based on predetermined cycletimes.

The buffer tank 108 functions as a “buffer” for the small holding tanks110 and large holding tank 112 by warming the water/muck/waste mixturebefore it is moved into the small holding tanks 110 and large holdingtank 112. That warming is preferably performed by a heat exchanger 156that is disposed in the buffer tank 108. The heat exchanger 156 receivesheat energy by pumping the heated and partially pasteurized or digestedwater/muck/waste produced with the small holding tanks 110 through theheat exchanger 156 before depositing it into the large holding tank 112.That exchange of heat energy is essential not only to complete thepasteurization process when pasteurization is necessary, but also toreduce the temperature of the heated and partially pasteurized ordigested water/muck/waste mixture to 35-40° C. before it is deposited inthe large holding tank 112.

That heated and partially pasteurized or digested water/muck/waste ispumped by a digester feed pump 132B that is controlled by the ECU 118and operates to feed the heated and partially pasteurized or digestedwater/muck/waste into the large holding tank 112. That operation notonly serves to pre-heat the water/muck/waste mixture before moving it tothe small holding tanks 110, it beneficially removes heat from theheated and partially pasteurized or digested water/muck/waste beforemoving it to the large holding tank 112. As discussed below, the heatedand partially pasteurized or digested water/muck/waste is preferablycooled down to about 40° C. before being depositing into the largeholding tank 112.

The waste piping 136B through which the pre-heated water/muck/waste ismoved to the small holding tanks 110 is preferably fitted within thefloor of the container 102 so the buffer tank 108 can be drained fromthe bottom and the small holding tanks 110 can be fed from the bottom.If space does not permit and the small holding tanks 110 must be fedfrom the top, the feed tubes preferably extend to the bottom of thebuffer tank 108 and/or each small holding tank 110 so that the mixturewill be withdrawn from the bottom of the buffer tank 108 and/ordeposited in the bottom of the small holding tanks 110. The buffer tank108 is preferably sized to allow continuous operation of the REMapparatus 100 for at least 2 days. And it is preferably made out ofsteel or fiberglass to reduce manufacturing costs.

The buffer tank air sparge system (not depicted) is designed to ensure acertain level of oxygen to be present inside the buffer tank 108, toprohibit the production of biogas inside the tank through the process ofanaerobic digestion. The air sparge system consists of a linear air pumpthat pumps air into an air-line. The air-line is led inside the tank tothe base of the tank, where it forms a perforated loop that allows aneven release of air. The linear air pump is electrically driven. It issized to deliver sufficient air to inhibit the production of biogas and,in case any gas is produced, to sufficiently dilute these gases toprevent a flammable or explosive condition inside the tank.

The buffer tank overflow system 1118 is a safety measure to preventoverfilling of the buffer tank 108. It comprises a permanentlynon-obstructed discharge point 1118 at the top of the buffer tank 108,which may connect to the central drainage line 1116 of the command unit902.

b. Small Holding Tanks 110

Returning to FIGS. 1A-1E, the pre-heated water/muck/waste is pumped fromthe buffer tank 108 to the small holding tanks 110 by a pasteurizationfeed pump 132C. That pump 132C operates on a predefined feeding cyclethat is controlled by the ECU 118. In the small holding tanks 110, thepre-heated water/muck/waste is heated and stirred to producepasteurization or, if pasteurization is not required for the overallanaerobic digestion process, to produce thermophilic anaerobicdigestion. The pre-heated water/muck/waste in each small holding tank110 is continuously stirred with a gas mixer 158 (FIG. 1E) to keep thesolids and liquids in suspension during the pasteurization orthermophilic anaerobic digestion process. That mixture is heated withheaters 160 (FIG. 1E) capable of heating the mixture contained thereinto around 55-75° C. The gas mixers 158 are pressurized with thecompressor 128 and include nozzles that inject air directly into thebottom of each small holding tank 110 to promote aerobic thermophilicdigestion, thereby supplementing the heating requirements duringpasteurization. And the heaters 140 are either electric immersionheaters or water-based boiler-fed coil heaters that are disposed in theinside of the small holding tanks 110 so that the water/muck/wastemixture can be heated directly.

Each of the small holding tanks 110 has a relatively small volume (e.g.,around 1,800 Liters) to reduce the energy required to heat thewater/muck/waste disposed therein. Loads on the heaters 160 can befurther reduced by recovering heat from the biogas engine 122 and/or theengines that drive the homogenizing pump 204, the de-watering unit 114,or any of the other pumps 132A-132D of the REM apparatus 100 in aregenerative manner so as to further increase the efficiency of the REMapparatus 100. And as discussed above, the small holding tanks 110 canbe used to perform either pasteurization or thermophilic anaerobicdigestion on the water/muck/waste disposed therein, depending on whetherpasteurization is required for the overall anaerobic digestion process.If they are used to perform thermophilic anaerobic digestion, biogaswill be generated in the small holding tanks 110 and similar precautionsto those discussed below with respect to the large holding tank 112 willneed to be taken (e.g., mixing the water/muck/waste with biogas insteadof air, drawing off biogas to the gas storage tank, separating the smalldigester tanks 110 from machinery and electronics that may produce aspark, etc.). The small holding tanks 110 may also be used for otherpurposes, such as arresting the digestion process of the grey water inthe liquor tank 126.

The small holding tanks 110 are operated in batch mode that includesoffset cycles of feeding, holding, and discharge. For example, after thefirst small holding tank 110 is fed and filled with pre-heatedwater/muck/waste from the buffer tank 108, it will hold that pre-heatedwater/muck/waste while it is stirred and heated, as discussed above. Thesecond small holding tank 110 will be fed and filled after the firstsmall holding tank 110. The heated and partially pasteurized or digestedwater/muck/waste will then be discharged from first small holding tank110 while the second small holding tank 110 holds, stirs, and heats thepre-heated water/muck/waste with which it was filled. And the heated andpartially pasteurized or digested water/muck/waste will then bedischarged from first second holding tank 110 while the second smallholding tank 110 is filled with a new batch of pre-heatedwater/muck/waste from the buffer tank 108. Water/waste/muck is cycledthrough the small holding tanks 110 in that manner as required isrepeated back and forth between the first and second digested tanks 110.The fill quantities are controlled by the ECU 118 using a set of levelsensors (LS) in the small holding tanks 110. And although only two smallholding tanks 110 are shown in FIGS. 1A-1E, the REM apparatus may use asmany small holding tanks 110 are required to meet a user's processingdemands.

The waste piping 136B through which the heated and partially pasteurizedor digested water/muck/waste is moved to heat exchanger 136 in thebuffer tank 108 is preferably fitted within the floor of the container102 so that mixture can be fed up through the bottom of the buffer tank108 so as to provide the proper temperature gradient (i.e., hottest onthe bottom and coolest on the top) as the heated and partiallypasteurized or digested water/waste/muck flows through the heatexchanger 156 in the buffer tank 108 and toward the large holding tank112. Each small holding tank 110 is insulated to improve its efficiency.Preferably, the small holding tanks 110 are formed from PVC to reducemanufacturing costs and a “green” material, such as sheepswool, is usedto form the insulation. The insulation can be formed in modular,interlocking pieces that can be connected together to surround the smallholding tanks 110.

Additionally, the small holding tanks 110 may be used to process greywater piped in from the liquor tank 126. Similar to the pasteurizationof the muck/waste, this process is designed to heat up thedigestate/liquor from the liquor tank 126 to a specified temperature andto maintain it at that temperature for a specified amount of time (i.e.the pasteurization process) before it is off-loaded from the system. TheREM apparatus 100 and 900 pasteurizes at a minimum temperature of 57° C.for a duration of five hours. These pasteurization characteristics arepreferably compliant with quality and controlling storage requirementsfor feedstock, thus qualifying the pasteurized liquor as a sellableliquid fertilizer.

This embodiment of the small holding tanks 110 has two cylindrical,polypropylene tanks, each with a capacity of approximately 1,000 liters.The small holding tanks 110 are connected to the odor abatement system908 through the odor abatement pipeline 1006, and are designed to bestructurally sound and to prevent leakage of any material or gases. Thetanks are insulated on all surfaces to reduce the transfer of thermalenergy away from the contents. Each tank incorporates a man-hole toprovide access to the inside of the tank for maintenance.

When full, the small holding tanks 110 are to be heated up to a minimumtemperature of 57° C. and maintained at that temperature for five hours.Transfer of thermal energy into the contents of each small holding tank110 is accomplished through an internal heat exchanger (not depicted),which consists of a stainless-steel coil that sits inside the smallholding tanks 110 and allows the thermal energy of hot water (suppliedfrom the CHP or boiler 922) to be transferred to the contents of thesmall holding tanks 110. The temperature is continuously measured viatemperature sensors mounted inside the small holding tanks 110 andregulated via a pneumatically operated 3-port control valve that isautomatically controlled by the main control system in reference to thesensor readings.

Each small holding tank 110 has a separate recirculation system 1114,designed to mix the content of the small holding tanks 110 and toprevent settling, separation or stratification of the liquor.Recirculation is provided through an electrically driven centrifugalpump 1114 mounted externally to the tank, with suction connected nearthe bottom of the tank and discharge 1108 connected towards the centerlevel of the tank.

Each small holding tank 110 has a separate air sparge system 1123,designed to ensure a certain level of oxygen to be present inside thetanks to prohibit the production of biogas inside the tank through theprocess of anaerobic digestion. The air sparge system 1123 consists of alinear air pump that pumps air into an air-line. The air-line is ledinside the tank to the base of the tank, where it forms a perforatedloop that allows an even release of air. The linear air pump iselectrically driven. It is sized to deliver sufficient air to inhibitthe production of biogas and, in case any gas is produced, tosufficiently dilute these gases to prevent a flammable or explosivecondition inside the tank.

The small holding tank 100 off-load system allows for pasteurizedliquor—classifiable as liquid fertilizer, or fertilizer—to beoff-loaded. The off-load system incorporates a single electricallydriven centrifugal pump mounted 1104 externally to the tanks, withsuction connected to both tanks. The discharge leads to a dischargepoint at the side of the command unit 902. At completion of an automatedpasteurization cycle in a small holding tank 110, the HMI will indicatethat the system is ready for fertilizer off-load. Starting the off-loadprocedure will cause the off-load pump 1104 to discharge the liquor tothe off-load point at the side of the command unit 902. The off-loadpoint is to be connected to the site-specific fertilizeroff-load/storage facilities (e.g. disconnectable flexible hosing leadinginto storage containers).

The small holding tank drainage system 1110 is used when a small holdingtank 110 needs to be emptied for maintenance purposes. The drainagesystem 1108 is connected from the bottom of each small holding tank 110to the central drainage line 1116 of the command unit 902 via a manuallyoperated ball valve.

c. Liquor Tank 126

The liquor tank 126 serves to hold the grey water, or liquor, that isseparated from the muck/waste through the de-watering unit 114. Theliquor tank can also be supplied liquor that is separated during any oneof the various processes in components 106-128. The liquor tank 126 isused to store liquor until it is needed for the various processes incomponents 106-128. For example, the liquor tank can be used to feedliquor back into the chopper unit 106 to aid in the dilution process.The liquor from the liquor tank 126 can alternatively be used to supplyliquor as needed to the buffer tank 108, small holding tanks 110, or thedigester unit 904 to aid in their respective processes.

In the embodiment depicted in FIGS. 1A-1E, the liquor tank 126 isdisposed adjacent to the first container 102 at a location near andbelow the de-watering tank 300 of the de-watering unit 114 so the solidfertilizer and liquid fertilizer produced with the de-watering unit 114can be gravity fed into the liquor tank 126. To serve that purpose, thede-watering tank 300 is disposed on a base 308 that supports it at alocation above the liquor tank 126. And although the liquor tank 126 isillustrated as being disposed adjacent to the first container 102, itmay also be disposed inside the first container 102 in a similarrelationship to the de-watering unit 114.

The liquor tank 126 may also be disposed adjacent to the first container102. And although the anaerobic digestion process may take a few weeksto complete, after the first cycle is complete, there should be solidand liquid fertilizers ready to be extracted each time the user goes toload the chopper unit 106 with new muck/waste. The solid fertilizer maybe mulch that is suitable for animal bedding. And at least a portion ofthe grey water may be re-circulated with the mixer feed pump 132A formixture with muck/waste that is loaded into the mixing tank 132 asrequired for hydrolysis. The re-circulation of the grey water with themixer feed pump 132A is controlled by the ECU 118 by automaticallyoperating that pump 132A and opening/closing the associated water valves134A as required to direct the flow of the grey water. The liquor tank126 is preferably made of PVC to reduce manufacturing costs.

In the embodiment depicted in FIGS. 9A, 9B, and 11, the liquor tank 126is housed in a separate container called the command unit 902. Theliquor tank 126 incorporates a man-hole for access to the inside of thetank for maintenance purposes. The liquor tank is connected to the odorabatement system 908 through the odor abatement pipeline 1006, and isdesigned to be structurally sound and to prevent leakage of any materialor gases. It is manufactured from materials that provide resistance tocorrosion and erosion for 20 years.

iv. Large Holding Tank 112

The heated and partially pasteurized or digested water/muck/waste ispumped from the small holding tanks 110 to the large tank 112 by thedigester feed pump 132B. Like the pasteurization feed pump 132C, thedigester feed pump 132B operates on a predefined feeding cycle that iscontrolled by the ECU 118. Because the heated and partially pasteurizedor digested water/muck/waste must be cooled to approximately 40° C.before it is deposited in the large holding tank 112, it passes throughthe heat exchanger 156 in the buffer tank 108 as it is pumped from thesmall holding tanks 110 to the large tank 112. The heated and partiallypasteurized or digested water/muck/waste is cooled by passing its heatenergy to the water/muck/waste mixture in the buffer tank 108 via theheat exchanger 156, as discussed above. In that manner, the heat energyexpended to support pasteurization or thermophilic anaerobic digestionin the small holding tanks 110 is re-used in a regenerative manner,thereby further increasing the efficiency of the REM apparatus 100.

In the large holding tank 112, the pasteurized or cooled and partiallydigested water/muck/waste is stirred to produce mesophilic anaerobicdigestion. Like the pre-heated water/muck/waste in each small holdingtank 110, the pasteurized or cooled and partially digestedwater/muck/waste in the large holding tank 112 is continuously stirredwith a gas mixer 158 (FIG. 1E) to keep the solids and liquids insuspension while biogas (e.g., methane and carbon dioxide) accumulatesat the top of the large holding tank 112. However, unlike the pre-heatedwater/muck/waste in each small holding tank 110, which is stirred withcompressed air from the compressor 128, the pasteurized or cooled andpartially digested water/muck/waste in the large holding tank 112 isstirred by re-circulating biogas through the gas mixer 158 using acorrosive gas vacuum pump 162. In the absence of air, bacterialpopulations break down organic solids in the water/muck/waste mixtureinto biogas and more stable solids. Thus, biogas is used to stir thewater/muck/waste instead of air because introducing oxygen into thatmixture would create an explosive atmosphere. In the alternative, amixing pump (not shown) could be used to mix the water/muck/wastemixture by intermittently circulating it within large holding tank 112.

The operating temperature of the large holding tank 112 is preferablybetween 32-40° C. Those lower temperatures allow the large holding tank112 be have a greater volume (e.g., around 14,000 Liters) than the smallholding tanks 110 because less energy is required to maintain thoselower temperatures. In fact, the large holding tank 112 may need to becooled instead of heated. To serve that purpose, the large holding tank112 may be made as a dual layer tank so that cooling fluid (e.g.,potable and/or grey water) can be circulated between the inner and outershells to cool the water/muck/waste disposed in the inner shell. The useof a conductive material, such as steel, on the inside shell and aninsulating material on the outside shell provide a suitable way ofachieving that functionality.

In the alternative, the large holding tank 112 may be formed as a singletank using low cost fiber reinforced thermoforms. That material allows aplurality of large holding tanks 112 to be rapidly manufactured usinginexpensive molds. That material is also flexible so the large holdingtanks 112 will not break if dropped when full of liquid (e.g., 1.5meters full moving at 20 kph). In either embodiment, the large holdingtank 112 may be painted with conditioned nanotech carbon in the shape ofa lotus leaf to repel bacteria and with silicates to prevent methanefrom tunneling/leaking through tank walls. The large holding tank 112 ispreferably immune to two types of bacteria-anammox bacteria andmethagenic bacteria, which are used to eat both ammonia and to breakdown carbon chains. The large holding tank 112 may also include acathode and anode that harvest free electrons from the digestion processso that the large holding tank 112 can be used as a big battery forpowering the REM apparatus 100 or for providing power to otherapparatus. The small holding tanks 110 may be similarly constructed.

The large holding tank 112 operates on a “draw and fill” mode where aknown quantity of water/muck/waste is drawn into the large holding tank112 by the digester feed pump 132C until it is filled to apre-determined level. The draw and fill quantities are controlled by theECU 118 using a set of level sensors (LS) in the large holding tank 112.The feed flowrate of water/muck/waste to the large holding tank 112 iscontrolled by the ECU 118 such that it provides a minimum retention timeof 15 days for the mesophilic anaerobic digestion process. And duringthe draw down process, biogas is preferably drawn back into the largeholding tank 112 from the gas storage tank 120 to maintain an operatingpressure of 15-20 mbar within the large holding tank 112.

The large holding tank 112 is sufficiently sealed to prevent gaseousoxygen from entering the system and hindering the anaerobic digestionprocess. The large holding tank 112 includes a safety relief valve 164that vents outside of the first container 102 and releases pressure fromthe large holding tank 112 if that pressure approaches unsafe levels.The large holding tank 112 is also insulated to improve its efficiency.Preferably, the outside shell of the large holding tank 112 is formed offiberglass to reduce manufacturing costs and a “green” material, such assheepswool, is used to form the insulation. The insulation can be formedin modular, interlocking pieces that can be connected together tosurround the large holding tank 112.

As mesophilic anaerobic digestion is performed in the large holding tank112, biogas collects at the top of the large holding tank 112. Althoughthe pneumatic pump re-circulates some of that biogas back into thewater/muck/waste as part of the mixing operation, the remainder of thebiogas is drawn from the large holding tank 112 and pumped through thegas scrubber 116 before being deposited in the gas storage tank 120.That biogas is preferably discharged from the large holding tank 112 atan operating pressure of 15-20 mbar. And after the mesophilic anaerobicdigestion process is completed, the digested water/muck/waste mixture ispumped to the de-watering unit 114 by a sludge draw-off pump 132D thatis controlled by the ECU 118 based on the retention time required forthe mesophilic anaerobic digestion process.

Because methane and other combustible gases are generated in the largeholding tank 112, it may be necessary to provide it in a separatecontainer from some of the other components of the REM apparatus 100—inparticular, those components that contain moving machinery andelectronics that may generate a spark (e.g., the chopper unit 106, thede-watering unit 114, the biogas engine 122, the air compressor 128, themixer feed pump 132A, the digester feed pump 132B, the pasteurizationfeed pump 132C, the sludge draw-off pump 132D, the gas vacuum pump 162,and the homogenizing pump 204). In the alternative, a container can bedivided into separate spaces using air-tight bulkheads to separate thelarge holding tank 112 from the machinery and electronics of the REMapparatus 100. Such a separate container or container space willpreferably provide full hazardous material and explosive atmosphereseparation from the machinery and electronics of the REM apparatus 100in accordance with local, national, and/or international standards, suchas the European Union's Atmospheres Explosibles (ATEX) directive andDangerous Substances and Explosive Atmospheres Regulations (DSEARs).

In the REM apparatus 100 and 900, the large holding tank 112 may beseparated into its own 20-foot container, the digester unit 904, asdepicted in FIGS. 9, 9B, and 12. This configuration provides thebenefits described above of separating a combustible component from therest of the REM apparatus 100 and 900. In one embodiment, the digesterunit 904 has the capacity to store approximately 20,000 liters ofdigestate. This separate digester unit 904 also gives the system theability to increase the number of digester units 904 while maintainingthe same number of chopper units 106 and command units 902. In addition,various sensors may be moved to a panel on the front of the container102 or 1000 to eliminate the need for ATEX sensors.

The buffer tank 108, the liquor tank 126, small holding tanks 110, andlarge holding tank 112 preferably are formed with conduit space in thecorners to allow for interior piping and cable connection. Quickdisconnections and pre-configured wiring harnesses may be accessedwithin this conduit space, which protects them from damage wheninstalling and/or transporting these tanks 108, 110, 112, and 126 and/ortheir respective containers 102, 1100, and 1200. The buffer tank 108,the liquor tank 126, small holding tanks 110, and large holding tank 112also preferably are formed with access hatches in the corners to allowaccess to the inside of the tanks 108, 110, 112, and 126 for performingmaintenance. For example, the access hatches allow a user of the REMapparatus 100 or 900 to access the sensors located within the tanks 108,110, 112, and 126.

v. De-Watering Unit 114

The de-watering unit 114 removes liquids from the fully digestedwater/muck/waste to produce a compost bi-product and thickened digestatethat can be used as solid and liquid fertilizers. In certain instances,it may be desirable for the liquid removed from the fully digestedwater/muck/waste to have zero Chemical Oxygen Demand, or COD. ChemicalOxygen Demand is the total measurement of all chemicals in the waterthat can be oxidized. Accordingly, the de-watering unit 114 to beconfigured to achieve zero COD.

As FIG. 3 illustrates, the de-watering unit 114 includes a de-wateringtank 300 where the digested water/muck/waste is received from the largeholding tank 112. The de-watering unit 114 also includes a conveyor tube302 and an electric motor 304 for rotating a shaftless screw conveyordisposed within the conveyor tube 302. As it rotates, the screw conveyortransports the solid muck/waste from the water/muck/waste mixture inde-watering tank 300 up through the conveyor tube 302 and out through aspout 306 disposed at the upper end of the conveyor tube 302. That solidmuck/waste can be collected in a bin placed below the spout on theloading platform 142 for use as solid fertilizer. And the remaining greywater, or liquor, in the de-watering tank 300 is then gravity fed intothe liquor tank 126 for use as liquid fertilizer.

The de-watering unit 114 may be disposed adjacent to the chopper unit106 at the same end of the first container 102 so that the process ofthe present invention is completed at the same location it begins.Accordingly, the user can load muck/waste into the chopper unit 106 andextract the resulting solid fertilizer produced via the anaerobicdigestion process at the same location. The liquor tank 126 may bedisposed adjacent to the first container 102 at that same end for thesame purpose. And although the anaerobic digestion process may take afew weeks to complete, after the first cycle is complete, there shouldbe solid and liquid fertilizers ready to be extracted each time the usergoes to load the chopper unit 106 with new muck/waste. The solidfertilizer may be mulch that is suitable for animal bedding. And atleast a portion of the grey water may be re-circulated with the mixerfeed pump 132A for mixture with muck/waste that is loaded into themixing tank 132 as required for hydrolysis. The re-circulation of thegrey water with the mixer feed pump 132A is controlled by the ECU 118 byautomatically operating that pump 132A and opening/closing theassociated water valves 134A as required to direct the flow of the greywater.

In the embodiment depicted in FIGS. 1A-1E, the liquor tank 126 isdisposed adjacent to the first container 102 at a location near andbelow the de-watering tank 300 of the de-watering unit 114 so the solidfertilizer and liquid fertilizer produced with the de-watering unit 114can be gravity fed into the liquor tank 126. To serve that purpose, thede-watering tank 300 is disposed on a base 308 that supports it at alocation above the liquor tank 126. And although the liquor tank 126 isillustrated as being disposed adjacent to the first container 102, itmay also be disposed inside the first container 102 in a similarrelationship to the de-watering unit 114.

The de-watering unit 114 may also include a bagging system 1302 in aseparate 20-foot container as depicted in FIG. 13. This bagging system1302 automatically takes the solid waste/muck to be used as fertilizerfrom the de-watering unit 114 and deposits it into various standardsized bags for periodic removal. For example, the bagging system 1302may automatically deposit solid waste/muck into 10 kg bags and conveythem into 1 m³ pallets that can then be easily removed by a standardforklift and loaded onto a flatbed for transportation of site.

The bagging system 1302 is controlled by the ECU 118 and removes theneed for manual unloading and packaging of the generated fertilizer. Thecontainer housing the bagging system 1302 may include level switchesconnected to the ECU 118 which monitor the container in order to avoidspillage. Additionally, the container may include grills/vents at thebottom of the container doors, and may include an extractor fan toprovide circulation to minimize odor within the container.Alternatively, the bagging system 1302 may be attached to the odorabatement pipeline 1006 to remove odor from the container. In someembodiments, the dewatering unit 114 and the liquor tank 126 may behoused in the same container as the bagging system 1302.

vi. Salt Management and Removal System

Depending on the location and type of waste being processed, it may benecessary for the REM apparatus 100 or 900 to process significantamounts of salty food waste. The REM apparatus 100 or 900 therefore mayinclude a salt management and removal unit. The salt management removalsystem relies on the various pumps and sensors in the various componentsof the REM apparatus 100 or 900 to monitor and control the salinity ofthe waste and the quality of biogas at various points during wasteprocessing. It also includes software executed by the ECU 118 to controlthe flow of waste and grey water in a manner that maintains the optimalamount of salinity in the various processes occurring within the REMapparatus 100 or 900.

The salt management removal system includes one or more sensors in thebuffer tank 108 measure salinity of the waste in the buffer tank 108 andone or more sensors in the large holding tank 112 to measure thesalinity of the waste and the quality of biogas in the large holdingtank 112. The ECU 118 compares the salinity measurements taken in thebuffer tank 108 and the large holding tank 112 and compares them to aset value representing the salinity of ocean water. The ECU 118 monitorsthe differences in salinity of the inbound waste in the buffer tank 108as compared to the salinity of waste being digested in the large holdingtank 112. The ECU 118 also monitors the quality and volume of biogas inthe large holding tank 112 and adjusts the inbound feed rate of wastefrom the buffer tank 108 to maximize biogas and methane production.There are a series of tables and self-learning algorithms in thesoftware executed by the ECU 118 that adjust any, some, or all of theparameters of the various processes occurring within the REM apparatus100 or 900 to maximize methane production in any given large holdingtank 112.

After digestion in the large holding tank 112 is completed, excessdigestate is offloaded to the liquor tank 126 before being pasteurizedin one or more small holding tanks 110 and then offloaded to thedewatering unit 114 for further processing to remove salt.

In addition, while the coagulated solids in the dewatering unit 114 maynot be salty, the separated water may contain excess salt. The saltmanagement and removal unit therefore is configured to remove salt fromthe separated water through a reverse osmosis process, which yields bothclean water and a salty brine. The clean water may be used as potablewater, or it may be returned to the buffer tank 108 as required todilute and/or reduce the salinity of incoming waste. The brine is driedinto a solid using heat provided from the CHP, while the vapor createdwhen drying the brine is captured as grey water that may bere-circulated to the mixing tank 132 by the mixer feed pump 132A.

vii. Gas Scrubber 116

The gas scrubber 116, or de-sulfurization unit, is disposed between thelarge holding tank 112 and the gas storage tank 120. It is configured toclean the biogas extracted from the water/muck/waste in the largeholding tank 112 before it is stored in the gas storage tank 120. Thegas scrubber 116 may be any suitable type, such as an activated carbonfilter or a compressed gas filter (e.g., an amine gas filter). The gasscrubber 116 is used to treat the biogas and refine it for use asfuel—namely by reducing the levels of hydrogen sulfide in the biogas.However, the gas scrubber 116 may not be needed if the biogas does notneed to be treated, such as when it is not going to be used for fuel ordoes not contain prohibited levels of certain chemicals.

viii. Electronic Control Unit (ECU) 118

The flow of liquid (e.g., potable and/or grey water), muck/waste, andbiogas through the REM apparatus 100 of the present invention iscontrolled by the ECU 118. As FIG. 4 illustrates, the ECU 118 includes aprogrammable logic controller (PLC) that is programmed to monitor,record, and control the various stages of the anaerobic digestionprocess (e.g., temperatures, volumes, and flow rates). It providesvisual feedback of those operations to the user via a graphical userinterface, such as a computer monitor or touchscreen. The ECU 118automates the anaerobic digestion process by turning the variouscomponents 106-128 of the REM apparatus 100 on and off based on thevalues it monitors and records. The ECU 118 makes the determination asto which components 106-128 to turn on and off primarily based on thecontent of the muck/waste loaded into the REM apparatus 100, which canbe detected with the appropriate sensors and/or can be input by a uservia a user interface at the ECU 118.

For example, the ECU 118 will automatically operate the appropriatepumps 132A-132D, 204, and 162 and open/close the appropriate valves134A-134C to pump the fully digested water/muck/waste from the largeholding tank 112 to the de-watering unit 114 after it detects that theanaerobic digestion process is completed. The ECU 118 will automaticallyfeed, hold, and discharge water/muck/waste from the small holding tanks110 in batch mode based on levels detected with level switches (LS) andthe times over which the water/muck/waste has been held in each smallholding tank 110. The ECU 118 will determine whether or not to activatethe heaters 160 in the small holding tanks 110 based on temperaturesensors (TS) in each small holding tank 110. And the ECU 118 willautomatically determine the flow rates and cycle times for moving thewater/muck/waste between the different components 106-128 of the REMapparatus 100 by monitoring the anaerobic digestion process in itsvarious stages using a clocking circuit, level sensors (LS) temperaturesensors (TS), and pressure sensors (PS) located throughout the REMapparatus 100, thereby allowing the ECU 118 to adjust the anaerobicdigestion process in real time as required to maintain optimaldigestion.

The ECU 118 can determine such things as the amount of liquid to add tothe muck/waste mixture and the amount of biogas expected to be producedfrom that muck/waste based on the answers to a series of questionspresented to the user via the graphical user interface of the ECU 118.For example, the user could be asked to input a description of the sitewhere the muck/waste was collected, the availability of services,waste/muck type (e.g., manure, vegetable waste, etc.), waste/muckquantities, the intended use of the mulch that will be produced, and theintended use of the grey water that will be produced. Thus, by allowinga user to input the answers to those questions for different batches ofmuck/waste loaded into the REM apparatus 100, the ECU 118 is able tocustomize the digestion process for each batch of muck/waste loaded intothe REM apparatus 100. Some of those answers may also be obtainedautomatically by the ECU 118, such as using a scale provided on thechopper unit 106 or the loading platform 142 to weigh the muck/wasteloaded into the REM apparatus 100.

The PLC of the ECU 118 is also programmed to monitor and maintain safetythroughout the anaerobic digestion process. That monitoring not onlyallows close control of machinery and electrical equipment to preventphysical injury to users, it also allows close control the processparameters that are used as Hazard Assessment and Critical ControlParameters (HACCPs). For example, the ECU 118 monitors the biogaspressure in the gas storage tank 120 and the levels of water/muck/wastein the small holding tanks 110 and large holding tank 112 to make surethey are maintained at safe operating levels (e.g., a level sensor (LS)will be provided in the small holding tanks 110 and large holding tank112 to ensure that the immersion heaters 160 are not trying to heat anempty tank). Alarms will sound if/when the volumes of biogas and/orvolumes of water/muck/waste approach unsafe levels. The ECU 118 alsoincludes a supervisory control and data acquisition (SCADA) interfaceand/or Internet and wireless (e.g., GSM, GPRS, wifi, etc.) functionalityfor providing the user with remote monitoring capabilities forefficiency, diagnostics, operations, and safety. Preferably, the ECU 118is provided at the same end of the first container 102 as the chopperunit 106, de-watering unit 114, and liquor tank 126 so the anaerobicdigestion process can be controlled from the same location thatmuck/waste is loaded into the REM apparatus 100 and fertilizer isremoved from the REM apparatus, thereby providing an added level ofconvenience to the user.

The ECU 118 includes a human-machine interface (HMI) for communicatingwith the various components 106-128, pumps 132A-132D, and valves134A-134C of the REM apparatus 100. It also includes a cloud monitoringapplication for regionally monitoring the status of those components106-128, pumps 132A-132D, and valves 134A-134C. Communication can beestablished with the ECU 118 via the SCADA interface and/or Internet andwireless functionality using substantially any computing device (e.g.,personal computer, laptop computer, tablet computer, personal digitalassistant (PDA), smart phone, etc.) so as to allow a user to remotelymonitor, control, and troubleshoot the REM apparatus 100. For example,smart phone applications can communicate with the ECU 118 via a businterface to a canbus node that communicates to low cost sensors anddevices, such as those used in the automotive industry.

All of the interfaces for a user to input information into and otherwisecontrol the operation of the ECU 118 are provide in the control box 148located on the facia 140 of the first container 102 so the user canoperate the different components 106-128 of the REM apparatus 100 fromthe same location where muck/waste is loaded into the REM apparatus 100and solid and liquid fertilizers are removed from the REM apparatus 100,thereby adding an additional level of convenience to the user. Thecontrol box 148 and its associated interfaces are in electrical datacommunication with the ECU 118 via electrical wiring 138. Or in thealternative, they may be in wireless data communication with each othervia any suitable, secure wireless functionality (e.g., GSM, GPRS, wifi,etc.).

The ECU 118 also provides a central source of power for the variouscomponents 106-128, pumps 132A-132D, and valves 134A-134C of the REMapparatus 100. It includes a miniature circuit breaker (MCB) for each ofthose components 106-128, pumps 132A-132D, and valves 134A-134C as wellas light emitting diodes (LEDs) that indicate their respective status(e.g., “on”, “fault”, etc.). Those MCBs may are accessible via a breakerbox 166 (FIG. 1A) disposed on the outside of the first container 102.The breaker box 166 is disposed on the outside of the first container102 so that those MCBs can be easily accessed without needing to go intothe container 102 where the risks of user injury are higher due to theamount of machinery housed therein. The other components of the ECU 118are preferably disposed in an enclosure inside the first container 102to provide better protection from the elements.

The power bus of the ECU 118 preferably receives its power from a 16amp, 240 volt mains power supply. It may also receive its power from thebiogas engine 122. And although FIG. 5 only shows four temperaturesensors (TS) and seven “low” level switches (LS), the ECU 118 isconnected to several other temperature sensors (TS) and level sensors(LS) to support its control of the REM apparatus 100. For example, theECU 118 also includes at least seven “high” level sensors (LS) and atleast three additional temperature sensors (TS). See, e.g., FIG. 1E. TheECU 118 may also be connected to other types of sensors, such as gascomposition sensors, pressure sensors (PS), voltmeters, etc., asrequired to support its control of the REM apparatus 100. The wiring 138of the ECU 118 and its various connections are compliant with the local,national, and/or international standards, such as those set forth in theWater Industry Mechanical and Electrical Specification (WIMES).

The ECU 118 may also be connected to a smart grid interface system toallow switching between heating and power sources. For example, the ECU118 may be connected to solar electric thermal panels to provide heatand power to various components in the REM apparatus 100. The ECU 118may switch between power and heating sources during operation asdetermined by the various sensors throughout the REM apparatus 100.

ix. Gas Storage Unit 906

After the biogas is extracted from the large holding tank 112, and afterit is cleaned by the gas scrubber 116 (when cleaning is required), it isstored in the gas storage tank 120 of the gas storage unit 906. As FIG.5 illustrates, the gas storage tank 120 includes a flexible bladder 500disposed inside a solid, double-walled tank 502. The double-walled tank502 may be filled with liquid (e.g., potable and/or grey water) andconstructed of a sufficiently strong material to withstand the highpressures associated with storing the biogas under pressure. The gasstorage tank 120 includes a water inlet 504 and a water outlet (notshown) so the liquid can be pumped into and out of the double-walledtank 502 via water piping 136A to equalize and maintain a constant,fixed pressure of biogas in the flexible bladder 500. The gas storagetank 120 also includes a safety relief valve 168 that vents outside ofthe second container 104 and releases pressure in the flexible bladder500 if that pressure approaches unsafe levels. Any surplus biogas thatcannot be stored by the gas storage tank 120 is safely burned off withthe flare 124 so as to prevent unsafe levels of pressure occurring. Thatflare 124 has a pilot light that is powered by a propane tank 170provided in or adjacent to the first container 102. The flare 124 alsomay have a water jacket (not depicted) that is fed with water from thesystem for use in heat absorption and boiling water, as discussed above.

To measure the volume of gas stored in the flexible bladder 500, aseparate flow meter is provided at the inlet and outlet gas piping 136Cof the gas storage tank 120. The difference between the readings atthose flow meters is used by the ECU 118 to monitor the amount of gasstored in the gas storage tank 120. Also provided at the outlet gaspiping 136C is a flow control valve 134C for controlling the flow ofbiogas from the gas storage tank 120 and a flame arrestor (not shown)for preventing a flame from propagating back through the flow controlvalve 134C into the gas storage tank 120. In that way, biogas can beextracted from the gas storage tank 120 as needed and used to generateheat, electricity, or any other form of gas-generated energy. One of thedevices that is used to generate heat and electricity is the biogasengine 122.

Because methane and other combustible gases are stored in the gasstorage tank 120, it may be necessary to provide it in a separatecontainer 104 from some of the other components of the REM apparatus 100or 900—in particular, those components that contain moving machinery andelectronics that may generate a spark (e.g., the chopper unit 106, thede-watering unit 114, the biogas engine 122, the air compressor 128, themixer feed pump 132A, the digester feed pump 132B, the pasteurizationfeed pump 132C, the sludge draw-off pump 132D, the gas vacuum pump 162,and the homogenizing pump 204). In the alternative, a container can bedivided into separate spaces using air-tight bulkheads to separate thelarge holding tank 112 from the machinery and electronics of the REMapparatus 100. Such a separate container or container space willpreferably provide full hazardous material and explosive atmosphereseparation from the machinery and electronics of the REM apparatus 100or 900 in accordance with local, national, and/or internationalstandards, such as the European Union's ATEX directive and DSEARs. Thegas storage tank 120 container 104, as designed, will have been testedand validated to withstand an explosion of a full gas storage tank 120pursuant to the theoretical explosion calculations of such standards.Preferably, all of the containers 102, 104, 1000, 1100, 1200, and 1300will have been tested and validated to these standards to ensures thatthe gas storage tank 120, and indeed the entire REM apparatus 100 and900, are safe to use in population centers such as inside large citybuildings.

As a further safety measure, each of the containers 102, 104, 1000,1100, 1200, and 1300 also preferably includes one or more pressurerelief devices (not depicted), such as pressure relief discs, that willrelease pressure within the container 102, 104, 1000, 1100, 1200, or1300 before it reaches unsafe levels. For example, pressure relief discscould be connected to the ECU 118 so that a signal is generated when apressure relief bursts, which would alert the operator of the REMapparatus 100 or 900 that pressure within one or more of the containers102, 104, 1000, 1100, 1200, and 1300 was approaching unsafe levels.

The gas storage unit 906 also may include a system to separate carbondioxide from methane (not depicted). The carbon dioxide extractionsystem uses various catalysts, combined with steam, to separate thecarbon dioxide and methane. This separated carbon dioxide may be fedback into the digester unit 904 to aid the mixing process. The use ofcarbon dioxide, when combined correctly in the digester unit 904 or inthe large holding tank 112, enhances the anaerobic digestion and mixingprocess instead of using biogas, as others in industry use it, to mixtheir digesters. The ECU 118 controls the mixing to manage the parasiticload of the system and the release of biogas. Continuous mixing isbeneficial for a huge parasitic load, while no mixing causes the systemto produce less biogas because fluid density prevents gas release.

Several different carbon dioxide separation systems can be used withinthe REM apparatus 100 and 900. One optional unit for carbon dioxideseparation is a three-stage compression system with a pump and vessel ateach stage, such that first pumping stage causes the sulfurous gasses toliquefy, the second stage liquefies carbon dioxide, and the third stageperforms compression. At each stage, the storage vessel may include ableeding line that allows the liquified gas to be released from thecombined vessel into another container for export. The liquified gas inthe storage vessels may also be recycled, through the bleeding line, bypumping the liquified gas into the digester for mixing. The liquifiedgas in the storage vessels may also be collected as a crude unrefinedgas to be used elsewhere, such as in greenhouses to increase plantproductivity, as understood by experts in the greenhouse trade.

The gas storage unit 906 also may incorporate a gas compression unit(not depicted) that compresses the biogas before it is stored in the gasstorage tank 120. Alternatively, the gas compression unit can be used tocompress excess biogas into separate storage units or standardized,portable compressed gas containers for use in mixing, as describedabove, or for use with other systems. This compression allows the gasstorage unit 906 to hold significantly more biogas, which allows the REMapparatus 100 or 900 to operate for several days with only a single gasstorage tank 120.

x. Biogas Engine 122

The outlet gas piping 136C from the gas storage tank 120 is connected tothe biogas engine 122, which simultaneously produces electricity andheat from the biogas via a combustion engine (e.g., an internalcombustion engine or a Stirling engine). The biogas engine 122 is sizedranging from a 5 kwhe to 50 kWhe combined heat and power (CHP) unit. TheCHP unit can be a modified diesel genset that burns biogas or apyrolsis-based syngas/biogas burning steam engine (e.g., a sterlingformat, a rotary piston engine, or an opposed piston engine that drivesa generator directly). In another embodiment, the biogas engine can be afuel cell module, with or without a steam reformer, designed to use themethane rich biogas. At its most complete, the CHP is a trigen systemwhich produces electricity, recovers the heat, and produces cooling.This system may have a heat storage unit to collect heat from either thesolar thermo/electric panel or the biogas engine 122.

Because the biogas engine 122 requires a specific input pressure tooperate (e.g., 100 mbar), biogas is maintained in the gas storage tank120 at that pressure using a booster fan 172. The electricity producedwith the biogas engine 122 can be linked to the user's power grid andused to power household devices, such as lights and appliances. And theheat produced can be linked to the user's heating, ventilation, and airconditioning (HVAC) system and/or water heating system and used forspace heating and/or water heating. The biogas engine 122 may also beused to power the various pumps 134A-134D, 204, and 162 of the REMapparatus, or any component 106-128 that runs on electricity, and toprovide heat to the small holding tanks 110 to further improve theefficiency of the present invention.

To further the mobility of the REM apparatus 100, the biogas engine 122is preferably provided on its own trailer. It is also preferablyconnected to the gas storage tank 120, the power bus of the ECU 118, anda user's power grid using standard connections.

In another embodiment, the biogas engine 122 may be used in conjunctionwith, or replaced with, a natural gas boiler system 922. The natural gasboiler 922 operates similarly to the biogas engine 122 in that itprocesses the biogas to generate electricity and heat. This boileroperates similarly to common natural gas boilers, though it may bemodified to specifically process the biogas generated through the REMapparatus 100 and 900 more efficiently. In one embodiment, the naturalgas boiler would use a heat-jacketed flare 124 to boil water to generateelectricity and heat for the REM apparatus 100 and 900.

xi. Flare 124

The flare 124 produces flame that burns surplus methane and/or propaneto the European Union's particulate standard. The flare 124 includes apilot light that is connected to the propane tank 170 via gas piping134B to ensure that surplus biogas is instantly lit and remains lit soit does not gather in unsafe, combustible amounts in and/or around theREM apparatus 100. The flare may include two separate pilot lights—afirst pilot light that burns methane and a second pilot light that burnspropane. A piezoelectric lighter or an auto ignition system with visualflame detection may also be used and integrated with the functionalityof the ECU 118 for automated triggering.

In another embodiment, the REM apparatus may use the biogas engine 122or the natural gas boiler 922 in place of the flare 124, or in additionto the flare 124. The natural gas boiler 922 takes the surplus methaneand/or propane from the various systems and uses it to create CHP topower the REM apparatus 100 or 900, rather than simply burning off theexcess biogas using the flare 124. Accordingly, the flare 124 may beoptional in certain configurations. The flare 124 also may be optionalin configurations that include the odor abatement system 908 disclosedin more detail below.

xii. Piping 136A-136C

a. Water Piping 136A

The water piping 136A may be any suitable low-pressure piping, such asPVC piping, for feeding liquid (e.g., potable and/or grey water) intothe chopper unit 106. As FIG. 6 illustrates, the water piping 136Adelivers potable water to the chopper unit 106 from an outside watersource, such as a well or a local utility, and delivers grey water tothe chopper unit 106 from the de-watering unit 114. To allow the REMapparatus 100 to be connected to an outside water source, the waterpiping 136A preferably includes a standard connector, such as a gardenhose connector, at an inlet location on the outside of the firstcontainer 102.

As FIG. 6 also illustrates, the grey water from the de-watering unit 114is circulated between the inner shell and outer shell of the largeholding tank 112 and between the outer shell and the bladder of the gasstorage tank 120 to aid in the cooling of the contents of the largeholding tank 112 and the gas storage tank 120. The ECU 118 controls theamount of cooling provided as required to maintain the desired operatingtemperatures in the large holding tank 112 and the gas storage tank 120by opening and closing the appropriate water valves 134A and operatingthe mixer feed pump 132A. And although FIG. 6 shows grey water beingpumped through both the large holding tank 112 and the gas storage tank120, one or both of those components 112 and 120 can be bypassed byopening and closing the appropriate water valves 134A.

b. Waste Piping 136B

The waste piping 136B provides a complex network that works its wayaround the fixed components 106-128 of the REM apparatus 100. Standardpipe lengths are used where possible to facilitate ease ofmanufacturing. The material used for the waste piping 136B is preferablyHDPE. The properties of that material allow it to withstand chemical andbiological attack, to withstand temperatures up to 137° C., and towithstand pressures up to 12 bar. Moreover, its insulating propertieshelp further improve the efficiency of the REM apparatus 100. A standarddrain connection is preferably provided on the outside of the firstcontainer 102 to facilitate connecting the waste piping 136B to a sumpfor draining the buffer tank 108, small holding tanks 110, large holdingtank 112, liquor tank 126, mixing tank 202, and de-watering tank 300 asrequired to clean and maintain them.

As FIG. 6 also illustrates, the waste piping 136B delivers thewater/muck/waste mixture to the buffer tank 108 before delivering it tothe small holding tanks 110. Then, the heated and partially pasteurizedor digested water/muck/waste mixture passes through the heat exchanger156 in the buffer tank 108 as it is moved from the small digesters tanks110 to the large holding tank 112. And after mesophilic anaerobicdigestion is completed in the large holding tank 112, the fully digestedwater/muck/waste mixture is moved to the de-watering unit 114. The ECU118 controls the amounts water/muck/waste moved between those components106-114 as required to optimize the anaerobic digestion process byopening and closing the appropriate waste valves 134E and operating thedigester feed pump 132B, the pasteurization feed pump 132C, the sludgedraw-off pump 132D, and the homogenizing pump 204. And although FIG. 6shows the heated and partially pasteurized or digested water/muck/wastemixture being pumped through the heat exchanger 156 in the buffer tank108, the heat exchanger 156 can be bypassed by opening and closing theappropriate waste valves 134B.

c. Gas Piping 136C

The gas piping 136C is preferably stainless steel due to the corrosiveproperties of elements within biogas. For example, there may be H2S(Hydrogen Sulfide) in the biogas. Stainless steel piping does not reactwith that medium. And as FIG. 7 illustrates, the gas piping 136C formstwo separate loops. The first loop circulates air through the smallholding tanks 110 with the compressor 128 to stir the water/muck/wastein the small holding tanks 110. And the second loop circulates biogasthrough the large holding tank 112 with the gas vacuum pump 162 to stirthe water/muck/waste in the large holding tank 112. The first loop is an“open” loop because it allows the introduction of air into the smallholding tanks 110, and the second loop is a “closed” loop because itonly utilizes the biogas already in the large holding tank 112.

The second loop also moves biogas from the large holding tank 112 to thegas storage tank 120 after scrubbing it with the gas scrubber 116. Fromthe gas storage tank 120, the scrubbed biogas is moved to the biogasengine 122 using a booster fan 172 to maintain the biogas at theoperating pressure required for the biogas engine 122. Any surplusbiogas that cannot be stored by the gas storage tank 120 is safelyburned off with the flare 124 so as to prevent unsafe levels of pressureoccurring. And as discussed above, biogas may be circulated back intothe large holding tank 112 to maintain the desired operating pressuretherein during the draw down process. The ECU 118 controls the amountsof biogas moved between those components 112, 116, 120, and 122 asrequired to perform those operations by opening and closing theappropriate gas valves 134C and operating the gas vacuum pump 162 andthe booster fan 172. And although FIG. 7 shows biogas being circulatedback into the large holding tank through the gas scrubber 116, the gasscrubber 116 can be bypassed to perform that operation by opening andclosing the appropriate gas valves 134C while the gas vacuum pump 162 isrun in reverse. And although FIG. 7 shows two separate loops, thoseloops may be interconnected as required to recover biogas from the smallholding tanks 110.

xiii. Odor Abatement System 908

To contend with the potentially bothersome odors generated by theanaerobic digestion process, the REM system 100 or 900 comprises an odorabatement system 908. The odor abatement system 908 receives atmospherefrom the odor abatement pipeline 1006. The odor abatement system 908then uses appropriate combination of odor abatement materials to filterout the odor to allow the atmosphere to be released without odor or needfor a flare 124. The odor abatement materials are contained withinspecial fabric bags that allow easy replacement. The odor abatement unit908 is manufactured from appropriate materials that provide resistanceto corrosion and erosion for 20 years. The bags with odor abatementmaterial may require replacement at six month intervals as a maintenanceitem.

In another embodiment, the buffer tank 108, small holding tanks 110,de-watering unit 114, and liquor tank 126 may each include an exhauststack 174 with a filter element. The filter element preferably utilizesorganic filtering material, such as a combination of steel wool andferns, to remove potentially bothersome odors from the gases generatedin those components 108, 110, 114, and 126. And the exhaust stacks 174preferably extend through the roof of the first container 102 so as tovent those gases outside of the first container 102. As discussed above,the large holding tank 112 does not include an exhaust stack 174 becausethe biogas generated therein is highly combustible. Accordingly, thatbiogas is either stored in the gas storage tank 120 or burned off by theflare 124. The exhaust stack 174 can be used in conjunction with theodor abatement system 908 to exhaust atmosphere when the odor abatementsystem is unable to process the excess atmosphere.

B. Method for Renewable Energy Microgeneration

The components 106-128 of the REM apparatus 100 are best described asforming separate nodes in the anaerobic digestion process. At node 1,the chopper unit 106 receives muck/waste (e.g., feedstocks) of variablesolids contents that have to be diluted down to about 8-10% total solidsand a ratio of about 1:4 of waste/muck to dilution liquid (e.g., potableor grey water). Dilution is achieved by adding the recycled grey waterrecovered from the fully digested water/muck/waste using the de-wateringunit 114 at node 6. Potable water can also be added from an outsidesource as required, such as when the REM apparatus 100 is firstcommissioned. The ECU 118 controls the dilution process based onmeasurements obtained with level sensing equipment.

After the required amount of dilution liquid (e.g., potable and/or greywater) is added to the muck/waste in the mixing tank 202, thehomogenizing pump 204 macerates the water/muck/waste mixture to obtainthe desired viscosity. That process should take only a few minutes aday, after which, there should be a sufficient amount of homogenizedwater/muck/waste to begin pasteurization and digestion. The homogenizingpump 204 is preferably configured to process 0.5 metric tons ofwaste/muck an hour. And as discussed above, the REM apparatus 100 can besized using modular components are required to process user-specificdaily amounts of muck/waste.

At node 2, the water/muck/waste mixture produced at node 1 istransferred into the buffer tank 108 for pre-heating. The buffer tank108 includes a heat exchanger 156 that cools the heated and partiallypasteurized or digested water/muck/waste produced during pasteurizationin the small holding tanks 110 at node 3 while warming thewater/muck/waste mixture produced with at node 1. The heat energy lostby the heated and partially pasteurized or digested water/muck/wasteduring cooling is transferred to the water/muck/waste mixture in thebuffer tank 108 to warm it from its ambient temperature before it ismoved to the small holding tanks 110. That process allows thewater/muck/waste mixture going into the large digester to be at 35-40°C. so as to avoid thermal shock to mesophilic bugs in the large holdingtank 112 at node 4. It also pre-heats the water/muck/waste mixtureproduced at node 1 so that less load is placed on the heaters 160 in thesmall holding tanks 110 at node 3, where the water/muck/waste mixture isheated to at least 70° C.

At node 3, the small holding tanks 110 use a gas mixer 158 to mix thewater/muck/waste mixture with air, which allows bugs to use oxygen toheat up the water/muck/waste mixture during pasteurization. The contentsof those small holding tanks 110 are also warmed with internal heaters160 to an operating temperature of approximately 70° C. for a minimum of60 minutes. That can be adjusted as required to optimize pasteurizationusing a SCADA system connected to the ECU 118 via the SCADA interface.Two or more small holding tanks 110 are preferably provided so that thebugs therein can be quickly and easily cycled through those tanks withfeed, hold, and discharge steps. The feed and discharge steps would bemore time consuming and difficult with larger tanks. Moreover, the loadon the heaters 160 would be greater in larger tanks.

After pasteurization in the small holding tanks 110 is completed, theheated and partially pasteurized or digested water/muck/waste is movedto the large holding tank 112 for mesophilic anaerobic digestions andbiogas recovery at nodes 4 and 5, respectively. As discussed above, thatheated and partially pasteurized or digested water/muck/waste is cooledto 35-40° C. by the heat exchanger 156 in the buffer tank 108 at node 2before it is deposited in the large holding tank 112 until apredetermined fill level is reached. In the large holding tank 112, thepasteurized or cooled and partially digested water/muck/waste iscontinuously stirred with the gas stirrer 158 by re-circulating thebiogas generated during mesophilic anaerobic digestion back into thewater/muck/waste. The feed flowrate to the large holding tank 112 issuch that it provides a minimum retention time of 15 days. Thetemperatures and times at which the water/muck/waste is held in thesmall holding tanks 110 and large holding tank 112 is controlled by theECU 118 so as to operate within the pertinent HACCPs and to comply withlocal, national, and/or international standards, such as U.S. EPAregulation 40 C.F.R. 503.32.

The biogas generated during mesophilic anaerobic digestion at node 4 isremoved from the large holding tank 112 and placed in the gas storagetank 120 at node 5. That biogas is moved to the gas storage tank 120 bythe gas vacuum pump 162 as it is being generated by the mesophilicanaerobic digestion. And after that process is complete, what remains ofthe water/muck/waste mixture is output to the de-watering unit 114 atnode 6. As the large holding tank 112 is being drawn down in thatmanner, biogas is moved from the gas storage tank 120 back into thelarge holding tank 112 so as to maintain an operating pressure of 15-20mbar in the large holding tank 112 during that draw-down process. Then,as the large holding tank 110 is being filled with the next batch ofpasteurized or cooled and partially digested water/muck/waste at node 4,the biogas is moved back into the gas storage tank 120 at node 5.

At node 6, the fully digested water/muck/waste drawn from the largeholding tanks 110 is pumped into the de-watering unit 114 forde-watering. The fully digested water/muck/waste undergoespre-filtration by passing it through fine mesh to aid in the separationprocess. The fully digested water/muck/waste may also undergodesulfurization hydrogen sulfide scrubbing, or sweetening, in thede-watering tank 300. And coagulant may be added to aggregate suspendedsolids in the fully digested water/muck/waste so that they fall to thebottom of the de-watering tank 300, thereby leaving a top layer ofcleaned “grey” water, or liquor, that is re-circulated back into thechopper unit 106 with the mixer feed pump 134B. The bacteria in the greywater can also be used as a feedstock, so it may also be gravity fed tothe liquor tank 126 for storage at node 7.

The solids that fall to the bottom of the de-watering tank 300 form athickened layer of organic fertilizer. The electric motor 304 of thede-watering unit 114 rotates the shaftless screw conveyor disposedwithin the conveyor tube 302 to transport that thickened layer oforganic, solid fertilizer up through the conveyor tube 302 and outthrough the spout 306 disposed at the upper end of the conveyor tube302, where it drops into a bin placed below the spout on the loadingplatform 142. The solid fertilizer, or mulch, collected in that bin ispreferably 75 to 85% dry as a result of that process. And the resultingsolid and liquid fertilizers produced by the digestion process willpreferably be pathogen free. This fertilizer can be certified aspathogen free with storage or additional heating in compliance withprescribed regulations.

C. Modular Configurations

Although only two containers 102 and 104 are discussed with respect tothe exemplary embodiments of the apparatus and method disclosed above,the components 106-128 of the REM apparatus 100 can be separated into asmany different containers 102, 104, 1000, 1100, 1200, and 1300 as arerequired to suit the particular application. For example, a processingcontainer (not depicted) could house the chopper unit 106, the buffertank 108, the de-watering unit 114, and the ECU 118; a digestioncontainer (not depicted) could house the small holding tanks 110, thelarge holding tank 112, and the gas scrubber 114; a CHP container (notdepicted) could house the biogas engine 122; a liquor storage container(not depicted) could house one or more liquor storage tanks 126; and agas storage container 104 could house one or more gas storage tanks 120.In that configuration, the processing container would process all of themuck/waste and water/muck/waste before and after the anaerobic digestionprocess; the digestion container would perform the pasteurization orthermophilic anaerobic digestion, the mesophilic anaerobic digestion,and the biogas scrubbing; and the gas storage container would performall of the biogas storage. One or more digestions containers couldthereby be added to the processing container and gas storage containeruntil the processing capacity of processing container and/or the storagecapacity of the gas storage container was reached. Accordingly, thosecontainers are preferably interconnected using standardized piping136A-136C and wiring 138 (e.g., prefabricated piping sections and wiringharnesses) to allow them to be connected in a modular manner, therebyallowing expansion of the REM apparatus 100 to suit substantially anythroughout requirement.

By way of more specific example, if the chopper unit 106 in eachprocessing container can process 0.5 metric tons of waste/muck an hour,a user that wants to process 6 metric tons of waste/muck in a 8-hour daycould obtain two processing containers and configure them to operate inunison, thereby allowing that user to process that amount of waste/muckover a 6-hour period. Similarly, two processing containers could beprovided to process 24 metric tons of waste/muck in a 24-hour period.Those two processing containers could then be connected to acorresponding number of digestion containers in a daisy chainconfiguration using the aforementioned standardized piping 136A-136C andwiring 138.

Because the anaerobic digestion process typically requires a ratio ofabout 1:4 of waste/muck to dilution liquid (e.g., potable and/or greywater), processing 6 metric tons of waste/muck a day will produceapproximately 30 tons of water/waste/muck mixture (6 metric tonswaste/mulch+(4×6) metric tons dilution liquid=30 metric tonswater/waste/muck mixture). And, because the digestion process in thelarge holding tanks 110 will take approximately twenty-one days,approximately 630 metric tons (^(˜)630 m³) of storage will be requiredto allow a continuous cycle of waste/muck to be processed at a rate of 6metric tons per day (30 metric tons/day×21 days/digestion cycle=630metric tons/digestion cycle). Thus, twelve digestion containers, eachhaving four 1,800 Liter small holding tanks and two 14,000 Liter largedigestion tanks 112, would be needed to digest 30 metric tons ofwater/waste/muck mixture in that 21-day period, as illustrated in FIG.8.

That 6-ton per day solution is estimated to create 600 m³ of biogas at55-60 percent methane. In such a large capacity process, two gas storagecontainers would need to be provided to store that biogas and at leasttwo CHP containers would need to be provided to convert that biogas intoheat and/or electricity, as also illustrated in FIG. 8. Preferably, atleast three biogas engines 122 will be provide between those two CHPcontainers so that two biogas engines 122 can be used to burn the biogasand the third can be used as a back-up.

Also in that 6-ton per day configuration, two liquor storage containerswould be needed to store the grey water removed from the fully digestedwater/muck/waste after anaerobic digestion is complete. A mulch storagecontainer may also be provided for storing the solid fertilizergenerated from the fully digested water/muck/waste after the grey wateris removed. Those additional containers are also illustrated in FIG. 8.

Each of the processing containers, digestion containers, CHP containers,liquor storage containers, gas storage containers, and mulch storagecontainers discussed above is preferably a standard 20-foot container.If a larger capacity of processing is required, 40-foot containers mayalso be used. And, if 40-foot containers are not suitable, modularcustom containers can be used to suite the required capacity. Thosecustom containers can be assembled on site from pre-formed insulatedconcrete or metal panels. The custom containers can be erected on aconcrete slab that is poured on site by wiring or bolting the pre-formedpanels together. The custom containers can be squared, can have roundededges, can have a domed roof, or any other suitable configuration.

The large holding tanks 112 can be formed in a substantially similarmanner if required. By way of example, if 24 metric tons of waste/muckis desired to be processed in a day, two processing containers can beprovided with three custom large holding tanks 112 formed as describedabove—two for storing the water/waste/muck mixture during the digestionprocess and one for holding that mixture if/when a problem occurs withone of the other large holding tanks.

By making the processing containers, digestion containers, CHPcontainers, liquor containers, gas storage containers, and mulch storagecontainers of the present invention modular, an REM apparatus 100 can beput together from those containers to suit substantially anyapplication. Thus, instead of having to build a new and different wastetreatment plant for every application, the REM apparatus 100 of thepresent invention can be sized to suit. Moreover, by separating thecomponents 106-114 in the processing containers and the biogas engines122 in the CHP containers from the small holding tanks 110, largeholding tanks 112, and gas storage tanks 120, the potential danger ofaccidentally igniting the biogas generated and/or stored in those tanksis avoided.

SUMMARY

In summary, the present invention provides a novel solution to wastedisposal problems while providing a sustainable source of energy. Afterthe present invention is installed, all the user needs to do is load hisor her waste into the apparatus and the system will process the waste toproduce heat, biogas, electricity, and fertilizer. And after only a fewweeks of use, the user will have a continuous supply of electricity. Thepresent invention provides at least the following advantages: 1) itgenerates electricity from horse muck year round; 2) it converts septicwaste into hot water and/or heat; 3) it eliminates the cost of disposal,unsightly muck heaps, and smelly septic systems; and 4) it generatesuseful bi-products, including solid and liquid fertilizers.

The REM apparatus 100 is an automated plant that requires nointervention except daily feeding with muck/waste. The embodiment ofFIGS. 1A-1E is capable of processing 400 kg of muck/waste (e.g.,feedstock) per day, which is digested over 15 days to produce about2,000 Liters of biogas and a pasteurized mulch product that meets orexceeds the PAS 110 quality protocol. The grey water, or liquor, alsomeets or exceeds that quality protocol. The REM apparatus 100 is alsodesigned to process muck/waste at temperatures and times within thepertinent HACCPs and that comply with U.S. EPA regulations (e.g., 40C.F.R. 503.32). As discussed above, the ECU 118 is programmed to controlthose temperatures and times. And proper separation of components106-128 is provided as required to comply with the European Union's ATEXdirective and DSEARs.

The apparatus and method of the present invention are particularlysuited for processing waste/much such as organic and septic waste,including but not limited to various types of farm animal manure (e.g.,horse, cow, pig, and chicken manure); meat, blood, and otherslaughterhouse waste; garden and agricultural green waste; foodpreparation and kitchen waste; wasted/leftover/spoiled food; and septictank contents. That muck/waste is digested with a mix of bacteria in ananaerobic digestion process to produce biogas (e.g., methane and carbondioxide), and what remains of the muck/waste after that process isseparated into a dry mulch and a liquid fertilizer. The biogas can becombusted in a CHP unit to generate heat and electrical power; the mulchcan be used as animal bedding; and the liquid fertilizer can be used toput back into the soil to increase its nutrient content and fertility.Moreover, excess electricity generated with the CHP can be sold back tothe national grid.

The foregoing description and drawings should be considered asillustrative only of the principles of the invention. The invention maybe configured in a variety of shapes and sizes and is not intended to belimited by the preferred embodiment. Numerous applications of theinvention will readily occur to those skilled in the art. For example,the mixers 138 may comprise rotational mechanical stirring devicesrather than air nozzles and the biogas engine 122 may be a biogasgenerator rather than a CHP. Therefore, it is not desired to limit theinvention to the specific examples disclosed or the exact constructionand operation shown and described. Rather, all suitable modificationsand equivalents may be resorted to, falling within the scope of theinvention.

What is claimed is:
 1. A portable and modular renewable energymicrogeneration apparatus comprising: a mixing tank that is configuredto mix incoming waste with a liquid; a buffer tank that is configured toreceive the waste from the mixing tank and pre-warm the waste inpreparation pasteurization; a pasteurization tank that is configured toperform pasteurization on the waste received from the buffer tank; adigestion tank that is configured to perform anaerobic digestion onwaste received from the pasteurization tank; a de-watering device thatis configured to separate liquid digestate and to remove salt from theliquid separated from the digestate; first sensors disposed in thebuffer tank and the digestion tank that are configured to measuresalinity; a second sensor disposed in the digestion tank that isconfigured to measure biogas quality; and a controller that isconfigured to: cause the transfer of digestate from the digestion tankto the pasteurization tank after anaerobic digestion of the wasteoccurs, cause the transfer of digestate from the pasteurization tank tothe dewatering device after the digestate received from the digestiontank is pasteurized in the tank pasteurization tank, cause thede-watering device to separate liquid from the digestate received fromthe pasteurization tank and to remove salt from the liquid separatedfrom the digestate to create a liquid with a reduced salinity, monitorthe salinity of liquid in the buffer tank and the digestion tank usingthe first sensors, monitor the quality of biogas in the digestion tankusing the second sensor, and cause the mixing of the liquid with thereduced salinity with the waste and adjust a feed rate of the waste tothe digestion tank as required to reduce the salinity of the waste andincrease methane production within the digestion tank.
 2. The apparatusof claim 1, further comprising a CO₂ extraction system configured to:separate CO₂ from the gas generated by the waste in at least one of themixing tank, the chopper, the buffer tank, the liquor tank, thepasteurization tank, and the digestion tank; and inject the CO₂ into thedigestion tank to stir the waste in the second holding tank.
 3. Theapparatus of claim 1, further comprising a natural gas boilingconfigured to generate at least of electricity and heat from gas removedfrom at least one of the mixing tank, the chopper, the buffer tank, theliquor tank, the pasteurization tank, and the digestion tank.
 4. Theapparatus of claim 1 comprising: a first modular unit comprising: themixing tank, and a chopper in fluid communication with the mixing tankthat is configured to reduce the waste to smaller sized components; asecond modular unit comprising: the buffer tank, a liquor tankconfigured to receive liquid removed from the digestion tank, the liquidreceived by the liquor tank being received for mixing with the waste inthe first modular unit, and the pasteurization tank; a third modularunit comprising the digestion tank; a fourth modular unit comprising agas storage tank that is configured to store gas generated by the wastein at least one of the mixing tank, the chopper, the buffer tank, theliquor tank, the pasteurization tank, the digestion tank, and the gasstorage tank; and wherein the first modular unit, the second modularunit, the third modular unit, and the fourth modular unit are portablein that they are configured to be transported to a site and placed influid communication with each other at the site, wherein the firstmodular unit, the second modular unit, the third modular unit, and thefourth modular unit are modular in that they can be combined with eachother in different numbers and configurations, and wherein each of themixing tank, the chopper, the buffer tank, the liquor tank, thepasteurization tank, and the gas storage tank is sized to supportanaerobic digestion in a plurality of third modular units.
 5. Theapparatus of claim 4, wherein the apparatus comprises a plurality offirst modular units and each of the plurality of first modular units isconfigured to receive different types of waste.
 6. The apparatus ofclaim 4, further comprising a fifth modular unit, the fifth modular unitcomprising the de-watering device, wherein the fifth modular unit isportable and modular in the same manner as the first modular unit, thesecond modular unit, the third modular unit, and the fourth modularunit.
 7. The apparatus of claim 6, wherein the fifth modular unitfurther comprises a containerizing system configured to place solidwaste output by the de-watering device into standard sized containers.8. The apparatus of claim 4, wherein each of the first modular unit, thesecond modular unit, the third modular unit, and the fourth modular unitis housed in a stackable container so that the first modular unit, thesecond modular unit, the third modular unit, and the fourth modular unitmay be stacked one on top of the other in different configurations. 9.The apparatus of claim 4, further comprising an odor management systemconfigured to: remove gas from within at least one of the first modularunit, the second modular unit, and the third modular unit; filter odorsfrom the gas removed from the at least one of the first modular unit,the second modular unit, and the third modular unit; and vent toatmosphere the gas removed from the at least one of the first modularunit, the second modular unit, and the third modular unit, wherein thegas removed from the at least one of the first modular unit, the secondmodular unit, and the third modular unit differs from the gas generatedby the waste in at least one of the mixing tank, the chopper, the buffertank, the liquor tank, the pasteurization tank, the digestion tank, andthe gas storage tank.
 10. The apparatus of claim 4, wherein: each of thefirst modular unit, the second modular unit, the third modular unit, andthe fourth modular unit is disposed in a portable container; and eachportable container is configured to withstand explosions of apredetermined magnitude without compromising an adjacent container. 11.The apparatus of claim 4, wherein: each of the first modular unit, thesecond modular unit, the third modular unit, and the fourth modular unitis disposed in a container; the first modular unit, the second modularunit, the third modular unit, and the fourth modular unit are configuredto be combined with each other in different numbers and configurationsusing piping and wiring disposed within the portable container of eachof the first modular unit, the second modular unit, the third modularunit, and the fourth modular unit; and the piping and wiring areconfigured to be connected and disconnected via connection points housedwithin the portable container of each of the first modular unit, thesecond modular unit, the third modular unit, and the fourth modularunit.